Open access peer-reviewed chapter

Polymer Nanocomposite-Based Electrochemical Sensors and Biosensors

Written By

Baiju John

Submitted: 14 November 2018 Reviewed: 13 May 2019 Published: 11 March 2020

DOI: 10.5772/intechopen.86826

From the Edited Volume

Nanorods and Nanocomposites

Edited by Morteza Sasani Ghamsari and Soumen Dhara

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Abstract

Polymer nanocomposites (PNCs) play a significant role in modern day life and are widely studied for extensive properties which make them appealing to numerous applications. They are synthesized with scalable processing procedures with several nanoscale variations of fillers and forms leading to specific sensing applications. In this chapter, PNC-based electrochemical sensors and biosensors like DNA biosensors and immunosensors are discussed. These sensors related PNC applications uses nanofillers of various combinations like conductive polymers with graphene (Grp), carbon nanotubes (CNTs), and metal nanoparticles, which endow high electrical conductivity, effective surface area, and fast electron transfer rate. Currently, wearable devices based on electrochemical Sensors and biosensors have been of great interest in the detection of both physiological and environmental analytes.

Keywords

  • polymer nanocomposites
  • electrochemical sensors
  • biosensors
  • DNA sensors
  • immunosensors

1. Introduction

Polymer nanocomposites (PNCs) have electrochemical properties as transducers which can be used for the manufacturing of electrochemical sensors and biosensors. They possess significant variations in responsiveness, synthesis, and morphology, which help in a significant level of variations in conductivity [1]. Afar from the economic aspect of the PNC-based sensors, the improved performance on the electronic side stands apart among its peers through the basal plane ratio of the nanofillers, method of doping, kinetic properties of the electrode, biological response and environmental impact [1]. The impact of nanofillers in PNCs plays a significant role in sensing, processing, and actuating capabilities of the electrodes of electrochemical and biosensing applications [2].

The “active states of PNCs” rests on three pillars: high electrical conductivity rate, large surface area and fast electron rate which leads to best electricidal sensor outcomes. PNCs helps in the material technological advancement of electrochemical sensors which have high sensitivity and selectivity, lower detection limits, reproducibility and stability as shown in Figure 1. All these increased used the PNCs in electrochemical sensor research which were manufactured through chemical synthesis or polymerization methods and could be easily scaled up for various applications [3]. The electrochemical sensors along with the immunosensors and biosensors are becoming the norm of the day. Detections limits and sensing technologies are improved consistently due to developments happening in the unique properties of PNCs especially conductivity and electrochemical activity. The interactive fillers facilitate ion diffusion that impacts the sensing applications through intercalation into the PNC matrices leading to better stability of active electron transfer sites and detection limits. These active fillers help in reducing the layer thickness in PNC leading to ultrathin electrochemical detector technology. PNCs stand as an outstanding leader with significant advantages in large specific interaction surface area, reduced dimension of fillers and efficient electron transfer rate [3].

Figure 1.

Key properties of PNC based electrochemical sensors and biosensors. With permission from Elsevier [1].

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2. Electrochemical sensors

PNCs are widely used in the development of electrochemical sensors. The electrochemical sensors are based on three categories of PNCs. PNCs of conductive polymers and inorganic nanomaterials, PNCs of conductive polymers and Grp, and PNCs of conductive polymers and CNTs. Once interaction has occurred between the PNC-based electrochemical sensors and the target analyte, an electronic signal is detected by the transduction system. The applications of PNC-based electrochemical sensors different materials are shown in Table 1.

Sensory materialAnalyteDetection limit
PPy-ZnO-PtXanthine0.8 μM
PPy-Pt-GCEHydrogen peroxide0.6 μM
PANI-TiO2-GCEGlucose0.5 μM
PANI-NiCo2O4-GCEGlucose0.3833 μM
PANI-Grp-GCE4-aminophenol6.5 × 10−8 M
PANI-Grp-ITOArtesunate0.012 ng mL−1
PANI-Grp-GCELercanidipine1.94 ng mL−1
PANI-Grp-GCENitazoxanide2.2 μg mL−1
PPy-Grp-GCEAdenine0.02 μM
Guanine0.01 μM
PPy-PIL-GO-GCEDopamine73.3 nM
PEDOT-rGO-GCEDopamine39.0 nM
PEDOT-Grp-GCEAscorbic acid2.0 μM
PANI-Grp-Bi2O3-GCEEtodolac10.03 ng mL−1
PANI-rGO-MIP-AuNP-GCESerotonin11.7 nmol L−1
PPy-MWCNT-ITOCholesterol0.04 mM L−1
PPy-MWCNT-GCEPemetrexed3.28 × 10−9 M
PEDOT-CNT-CPEHydroquinone0.3 μM
PEDOT-CNT-CPEDopamine20.0 nM
PEDOT-CNT-CPENitrobenzene83.0 nM

Table 1.

Electrochemical sensors based on polymer nanocomposites [1].

2.1 Polymer nanocomposites based on conductive polymers and inorganic nanomaterials

Metal and metal oxide nanoparticles have been extensively studied as electrochemical sensing materials due to such beneficial features as their small size; unique chemical, physical, and electronic properties; flexibility in fabricating novel and improved sensing devices; and good sensitivity to the ambient conditions are shown in Table 1. The assimilation of nanoparticles of metals into PNC matrices set the stage for enhanced electrocatalytic electrode detection leading to multiple modern-day applications. For example, a Zinc oxide nanoparticle intercalated into polypyrrole (ZnO-PPy) PNC showed excellent Xanthine detection by through xanthine oxidase enzyme immobilization [4]. A glassy carbon electrode (GCE) modified with ultrathin polypyrrole nanosheets decorated with Ag nanoparticles was fabricated for the detection of hydrogen peroxide (H2O2). The modified device showed high sensitivity toward the reduction of H2O2 [5]. Similar electrochemical sensor based on polypyrrole–platinum (PPy-Pt) PNC was fabricated for the detection of H2O2 [6]. Another voltammetric sensor based on a polyaniline-gold nanoparticle (PANI-AuNP) PNC deposited on GCE was used for the detection of epinephrine (EP) and uric acid (UA) [6]. Exploiting the advantages of PNCs, two GCEs modified with PANI-TiO2 and PANI-NiCo2O4 PNC-based electrochemical sensors were developed for the detection of glucose [7]. TiO2 nanotubes (TNTs) was intercalated into a PANI-TNT PNC composite for through hydrothermal method for the detection (a reported sensitivity of 11.4 μA mM−1) of glucose (a reported sensitivity of 11.4 μA mM−1) by the immobilization of glucose oxidase (GOD) [7].

2.2 Polymer nanocomposites based on conductive polymers and graphene

Graphene (Grp), an allotrope of carbon, has become the new material of interest and widely integrated into the sensor research from the beginning of this millennium due to its unique properties of electrical conduction and 2-dimensional existence. Grp-PNC-based electrochemical sensors are used for electroanalytical detection of target molecules with high precision of selectivity and sensitivity as shown in Table 1, which showed spectacular detection limits over a wide range. An electrochemical sensor fabricated for the detection of 4-aminophenol (4-AP) using a PANI-Grp-GCE-modified device showed a detection limit of 6.5 × 10−8 M and sensitivity of 604.2 μAmM−1 [8]. A sensor was fabricated with a PANI-Grp-based PNC onto an ITO plate with immobilized horseradish peroxidase enzyme with a sensitivity limit of 0.15 mA ng mL−1 [9]. A PANI-Grp-GCE-based PNC sensor for the elimination of calcium antagonist lercanidipine in pharmaceutical formulations for medical purposes showed a detection limit in the range from 5 to 125 ng mL−1 [10]. The same PANI-Grp-GCE-based PNC sensor showed the detection of nitazoxanide compound which was an added advantage [11]. Electrochemical sensors based on PPy-based PNC are becoming popular these days due to their specific applications through their overoxidized form polypyrrole (PPyox). Fabrication of polypyrrole-graphene (PPyox/Grp) helped in the simultaneous detection of adenine and guanine through an electrodeposition method. PPy-Grp composite was electro-polymerized with pyrrole and graphene oxide (GO), followed by electrochemical reduction of GO composite. The electrochemical sensor’s significant improvement in the sensing of adenine and guanine is due to the specific structure of the nanocomposite. The adenine and guanine showed strong π-π interactions, and cationic selectivity [12].

The detection of Dopamine (DA) using PNCs was the holy grail in neurochemical studies ad it is a prominent neurotransmitter, which plays a role in neurological disorders such as Parkinson’s disease and schizophrenia [13]. A poly(ionic liquid)-functionalized polypyrrole-graphene oxide (PIL-PPy-GO)-based PNC electrochemical sensor was fabricated by the polymerization of 1-vinyl-3-ethylimidazolium bromide on N-vinyl imidazolium-modified PPy-GO films. The PILs helped in changing the surface charge which dispersibility of the PIL-PPy-GO composite and helped in the detection of DA [14]. Another sensor used for the detection of DA was a PNC-based poly (3,4-ethylene dioxythiophene)-graphene oxide (PEDOT-GO) fabricated by electrodeposition showed significant sensing capabilities [15]. A one-step electrochemical redox synthesis process of PEDOT-Grp PNC film was done using simultaneous electrodeposition of PEDOT and electrochemical reduction of GO on a GCE with high detection sensing of the ascorbic acid molecules. In this sensor PEDOT-Grp thin film PNC mediated the electron transfer between AO and electrode interface resulting in significant improvement in electrocatalytic activity and sensitivity of ascorbic acid molecules [16]. Jain et al. [5] introduced the combination of Grp and a conducting PANI-Bi2O3 PNC, the synergic effect of which enhanced the performance of sensors used for the electrocatalytic oxidation of etodolac in pharmaceutical formulations.

In recent years, molecularly imprinted polymers (MIPs) with high selectivity, affinity, chemical stability, and easy preparation for the template molecule are a promising candidate for developing a new generation of recognition elements for sensors. A double-layered membrane-sensing interface was fabricated based on rGO-PANI nanocomposites and MIPs embedded with AuNPs for sensitive and selective detection of serotonin (5-hydroxytryptamine, 5-HT). The obtained sensor showed remarkable selectivity to serotonin against the interferences caused by ascorbic acid and other interferents with a good detection limit of 11.7 nmol L−1 [17].

2.3 Polymer nanocomposites based on conductive polymers and carbon nanotubes

PNCs based on conductive polymers helped in improving the sensing properties of the electrochemical sensors with enhanced selectivity and stability. Some of the popular CNT-based PNC reported in the literature are shown in Table 1. A PPy-multiwalled carbon nanotube (MWCNT)-toluene sulfonic acid-based PNC was fabricated fr the detection of cholesterol with ITO-coated glass was the substrate for the sensor. The sensor showed high sensitivity and a fast response time of 9 s [18]. Sodium dodecyl sulfate-doped PPyox) with carboxylic acid functionalized MWCNT-modified GCE were reported for the detection of the anticancer drug pemetrexed (PMX). The results showed that overoxidation of the PPy film conferred a negative charge density on the porous layer, which in turn enhances the adsorption of PMX [19]. Xu et al. fabricated a carbon paste electrode (CPE) modified with a PEDOT-CNT nanocomposite. They used this electrode for the analysis of hydroquinone, DA, and nitrobenzene [20].

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3. DNA biosensors

PNCs are widely used these days in DNA biosensors. The medico biological field is growing leaping and bounds. In this era of 23 and me everything possible with DNA is bouncing through the boundaries of technology like DNA CRISPR editing, gene mapping. Biological agents for nefarious purposes and forensics. A basic DNA sensor work on a simple principle. You plant a DNA probe on a surface and this planted DNA chain hybridizes with its complementary pair. This hybridization technically called transduction can be detected optically and electrochemically. The electrochemical detection of transducers through electrochemical sensors leads us to DNA biosensors and are now extremely popular. The recent progress in the studies is summarized in Table 2 and discussed in the section below.

SensorAnalyteDetection limit
PANI-AuNP-GS-Cts-GCEBCR/ABL fusion gene2.11 pM
PANI-AuNP-AuSilver ions10 pM
PANI-AuNP-AuDNA sequence associated with S. aureus150 pM–1 μM
PPy-PANI-AuNP-Au15-mer DNA oligonucleotides1.0 × 10−13 M
PPy-PEDOT-AgNP-GCE27-mer DNA oligonucleotides5.4 ± 0.3 × 10−15 M
PANI-Fe3O4-CNT-ITONeisseria gonorrhoeae1 × 10−19 M
PANI-AuNP-GSPEmicroRNA-160.1 nM

Table 2.

Polymer nanocomposite-based DNA sensors [1].

The schematic illustration of the most popular DNA biosensor based on polyaniline-gold nanoparticle-chitosan-graphene sheet (PANI-AuNP-Cts-GS) composite with a functional capture probe for the detection of BCR/ABL fusion gene in chronic myelogenous leukemia (CML) is shown in Figure 2. The capture probe used a hairpin structure and was dually labeled with a 5′-SH and a 3′-biotin. The biotin electrode probe was used for the detection of streptavidin–alkaline phosphatase (AP) enzyme which in turn cause an electrochemical signal caused by the catalytic reduction of 1-naphthyl phosphate to 1-naphthol picked up by Diffuse Pulse Voltammetry (DPV) with a detection range of 10–1000 pM [21]. A DNA biosensor fabricated with PANI–AuNP PNC was used for the detection of Ag+. It works on the following principle: the electrochemical biosensor regenerates cysteine leading to the release of Ag+ from the cytosine to Ag+-Cytosine complex and reused again. The fabricated biosensor showed excellent selectivity with a good detection limit for silver ions [22]. Another DNA electrochemical biosensor was developed using polyaniline nanofibers (PANI-nf) enrapturing AuNPs making (PANI-nf-AuNP), a PNC. Gold was used as the electrode for the detection of Staphylococcus aureus DNA from the PANI-nf-AuNPs sensor, where the detection concentration varied from 150 × 10−12 to 1 × 10−6 mol L−1 [23]. A DNA biosensor based on the PANI-Fe3O4-CNT PNC was manufactured for sensing Neisseria gonorrhoeae through a DNA probe. The fabricated biosensor showed sensing in the range from 1 × 10−19to 1 × 10−6 M through DPV measurements [24]. The most recent DNA biosensor based on PANI-AuNPs PNC detected the microRNA-16 using a streptavidin-AP conjugate to biotinylated target sequences through transduction with a detection limit of 0.1 nM [25]. DNA biosensor made with polypyrrole-polyaniline-gold (PPy-PANI-Au) PNC responded to the target DNA through transduction, noncomplementary and single- and double-base-mismatched target DNA-chains with a detection limit between 1 × 10–6 and 1 × 10−13 M [26]. Nanotube DNA biosensor based on polypyrrole and poly(3,4-ethylenedioxythiophene) (PPy-PEDOT) PNC, which was functionalized with Ag nanoparticles sensed DNA transduction through EIS detection. The DNA chains used for detection were thiol-capped on the modified sensor [27].

Figure 2.

Schematic illustration of the DNA sensor construction process. With permission from Elsevier [1].

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4. Electrochemical immunosensors

PNCs are superior candidates for the fabrication of electrochemical Immunosensors, where the antibodies are the probes which form ionic complexes with the corresponding antigen pair with a specific target. Electrochemical Immunosensors are becoming widely used in clinical diagnosis applications, doping or impurities or detecting biological components in the food industry and detecting the biomolecules of environmental origin and impact. The most widely reported are discussed in this section and shown in Table 3. The immunosensors based on CNT-PPy-goat IgGs showed the interaction between the goat IgGs and its anti-goat IgGs, which changes the charges at the sensor surface with changes in conductance level. The response time for the anti-goat IgG was 1 min [28]. A label-free impedance immunosensor for human chorionic gonadotropin (hCG) detection using a PPy-PPa-hCG-modified carbon ink electrode was fabricated by the deposition of a PPy-pyrole-2-carboxylic acid copolymer. The hCG antibody was immobilized via the COOH groups of pyrrole-2-carboxylic acid, as a linker for covalent biomolecular immobilization. This immunosensor has a detection limit of the hCG antigen was in the range of 100 pg mL−1 to 40 ng mL−1 [29]. The next progress was PANI-AuNP hybrid electrochemical immunosensor with the gold electrode for the detection of prostate antigen (PSA). The immunosensor showed effective immobilization of anti-PSA with excellent sensing performance (1.4 μA M−1) and detection limit (0.6 pg mL−1) through effective electron transport [30]. For the detection of aflatoxin B1, an electrochemical immunosensor based on a Grp-CP-AuNP-IL composite film was used. The fabrication was in a five-part series mode as Grp-CP-AuNP-IL pattern. Poly(DPB), 2,5-di-(2-thienyl)-1-pyrrole-1-(p-benzoic acid) helped in the electrochemical stability as a CP. The covalent bonding through the antibody immobilization via carbonyl groups of the polymer helped in preventing the antibody loss, resulting in a detection limit of 1.0 fM [31]. For ofloxacin detection, an immunosensor was fabricated based on a dual-amplification mechanism resulting from Au nanoclusters embedded in the pre-synthesized PPy film as the sensor platform and multienzyme antibody-functionalized gold nanorods as the label. The electrochemical response was in the range of 0.08 and 410 ng mL−1 with a low detection limit of 0.03 ng mL−1 [32].

SensorAnalyteDetection limit
CNT-PPy-microelectrodeAnti-goat IgG0.05 μg mL−1
PPy-PPa-carbon inkhC2.3 pg mL−1
PANI-AuNP-AuProstate-specific antigen0.6 pg mL−1
Grp-DPB-AuNP-AuAflatoxin B11.0 fM
Au-PPy-GCEOfloxacin0.03 ng mL−1
Grp-AuNP-DPB-AuNPs-IL-GCEMicrocystin-LR3.7 × 10−17 M
Grp-PANI-GCEEstradiol0.02 ng mL−1
PANI-GO-CdSe-GCEInterleukin-60.17 pg mL−1
PEDOT-AuNP-ZnSe-Azure I-PtAlpha-Fetoprotein1.1 fg mL−1
PANI-AuNP-PWECarcinoembryonic antigen0.50 pg mL−1
α-fetoprotein0.80 pg mL−1
pPPA-MWCNT-GCEProlactin3 pg mL−1
Pt(MPA)NP-PPy-ITOC-reactive protein (αCRP)4.54 ng mL−1
PPy-PPa-rGOAflatoxin B110 fg mL−1
PANI-Au-AMNP-NPGCarbohydrate antigen 72-40.10 U mL−1
AuNP-FC-PANI-GCECarcinoembryonic antigen0.1 pg mL−1

Table 3.

Electrochemical immunosensors based on polymer nanocomposite [1].

An electrochemical immunosensor was fabricated a PNC-based Grp-AuNP-poly-DPB-AuNP-IL for the detection of microcystin-LR through electrodeposition method on GCE. In this electrochemical sensor, the Grp-gold helped in the electron transfer of [Fe(CN)6]3-, and the poly 2,5-di-(2-thienyl)-1-pyrrole-1-(p-benzoic acid)- gold nanoparticle (poly-DPB-AuNP) enhanced the electrical conduction and subsequent immobilization of the microcystin-LR antibody [33]. A Grp-PANI-based PNC electrochemical sensor for the estradiol using horseradish peroxidase-graphene oxide-antibody (HRP-GO-Ab) was designed where carboxylated GO serves the antibody carrier property while the horseradish peroxidase helped in catalytic hydrogen reduction on the electrode. This estradiol immunosensor detected the estradiol in tap water and milk samples, with average recoveries of 97.25% and 96.6%, respectively [34]. The electrochemical immunosensors with electrochemiluminescence (ECL) sensing property was achieved through Quantum dots (QDs). This was based on graphene oxide nanosheet–polyaniline nanowire-CdSe quantum dot (GO-PANI-CdSe) which detected human interleukin-6 (IL-6) [35]. A ZnSe QD-Azure I-AuNP-PEDOT-modified Pt electrode electrochemical immunosensor helped in the detection of alpha-fetoprotein (AFP) through electrochemiluminescence (ECL) sensing (detection limit ~1.1 fg mL−1). The sensing mechanism was as follows: ZnSe QDs immobilize the antibody, the nanoAu-PEDOT facilitated the electron transfer, and Azure I did the catalytic reduction of redox dye with two active amino groups [36].

PANI-AuNP-modified paper working electrodes (PANI-AuNP PWEs) were fabricated for the simultaneous determination of two tumor markers, carcinoembryonic antigen (CEA) and AFP, in real human serum samples [37]. An electrochemical immunosensor for prolactin hormone was also constructed by immobilizing the antigen onto poly (pyrrolepropionic acid) CP and carbon nanotube (pPPA/CNT) hybrids deposited onto a GCE and labeled with AP enzyme with a reported detection limit of 104 ng mL−1 [38]. Polypyrrole (PPy)-based PNC was used to manufacture a bioelectrode for the detection of human C-reactive protein antigen (Ag-αCRP). This was made possible with the inorganic nanoparticles (3-mercaptopropionic acid (MPA)-capped Pt nanoparticles. First, the Ab-αCRP was immobilized covalently through specific carboxyl groups linkages through Pt(MPA)- NPs within the polypyrrole (PPy)-based PNC film by carbodiimide coupling. The resulted electrochemical immunosensor showed excellent fine probe orientation with a detection capacity of 10 ng mL−1–10 μg mL−1 [39]. Another label-free impedimetric immunosensor based on multifunctional PNCs was based on (polypyrrole–pyrrolepropylic acid–reduced graphene oxide (PPy-PPa-rGO)) for the detection of mycotoxin aflatoxin B1 [40]. An enzyme-free electrochemical immunosensor modeled on the sandwich pattern was used for the detection of carbohydrate antigen 72–4 (CA72–4). The sensing electrode was nanoporous gold (NPG) film and asymmetric multicomponent (AMNPs) nanoparticles based on PANI-Au was used as labels. The NPG helped in the creased immobilization of Ab1 on the electrode, while the PANI-Au AMNPs impacted on the reduction capability of the electrochemical immunosensor [41]. The doping of AuNPs and PANI films with potassium ferricyanide over a gold electrode was used to detect a carcinoembryonic antigen (CEA). This PNC-based biocompatible electrochemical immunosensor showed excellent conductivity and redox electroactivity. The detection of CEA was analyzed through electrode response of [Fe(CN)6]3− as the redox mediator [42].

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5. Conclusion

PNCs have been explored for the construction of novel biosensors using PNC like materials as sensing elements. The efficient combination of different nanoscaled materials with good conductive polymers open a new avenue for utilizing novel PNCs as enhanced elements for constructing electrochemical sensing platforms with high performance. Health monitoring wearable tech like Fitbit or Apple Watch are all based on the PNC electrochemical sensors are of great interest in the health industry for the detection of physiological parameters of the human body. The progress of PNC-based wearable electrochemical sensors to analyses biochemical fluids other than blood such as interstitial fluids, sweat, tears, and saliva invoked interests in Silicon Valley echelons like Google, OrSense, and NovioSense which made the sector more interesting. Another significant challenge is the technical challenges to the wearability of the PNC-based material for manufacturing the same which includes analytical performance and biocompatibility. There is significant progress reported on the PANI-based wearable immunosensor used for epidermal pH monitoring. With all these advances the future of PNC-based devices is promising and applications shall reach out to commercial sensing applications like military, health-care and community fitness initiatives.

References

  1. 1. Shrivastava S, Jadon N, Jain R. Next-generation polymer nanocomposite-based electrochemical sensors and biosensors: A review. Trends in Analytical Chemistry. 2016;82:55-67. DOI: 10.1016/j.trac.2016.04.005
  2. 2. Wallace GG, Smyth M, Zhao H. Conducting electroactive polymer-based biosensors. Trends in Analytical Chemistry. 1999;18:245-251. DOI: 10.1016/S0165-9936(98)00113-7
  3. 3. Gangopadhyay R, Amitabha D. Conducting polymer nanocomposites: A brief overview. Chemistry of Materials. 2000;12:608-622. DOI: 10.1021/cm990537f
  4. 4. Devi R, Thakur M, Pundir CS. Construction and application of an amperometric xanthine biosensor based on zinc oxide nanoparticlespolypyrrole composite film. Biosensors & Bioelectronics. 2011;26:3420-3426. DOI: 10.1016/j.bios.2011.01.014
  5. 5. Xing L, Rong Q , Ma Z. Non-enzymatic electrochemical sensing of hydrogen peroxide based on polypyrrole/platinum nanocomposites. Sensors and Actuators B: Chemical. 2015;221:242-247. DOI: 10.1016/j.snb.2015.06.078
  6. 6. Yu Z, Li H, Zhang X, Liu N, Tan W, Zhang X, et al. Facile synthesis of NiCo2O4@Polyaniline core-shell nanocomposite for sensitive determination of glucose. Biosensors & Bioelectronics. 2016;75:161-165. DOI: 10.1016/j.bios.2015.08.024
  7. 7. Fan Y, Liu JH, Yang CP, Yu M, Liu P. Graphene-polyaniline composite film modified electrode for voltammetric determination of 4-aminophenol. Sensors and Actuators B: Chemical. 2011;157:669-674. DOI: 10.1016/j.snb.2011.05.053
  8. 8. Radhapyari K, Kotoky P, Das MR, Khan R. Graphene-polyaniline nanocomposite based biosensor for detection of antimalarial drug artesunate in pharmaceutical formulation and biological fluids. Talanta. 2013;111:47-53. DOI: 10.1016/j.talanta.2013.03.020
  9. 9. Jain R, Tiwari DC, Shrivastava S. A sensitive voltammetric sensor based on synergistic effect of graphene-polyaniline hybrid film for quantification of calcium antagonist lercanidipine. Journal of Applied Polymer Science. 2014;131:40959-40965. DOI: 10.1149/2.018404jes
  10. 10. Jain R, Tiwari DC, Karolia P. Electrocatalytic detection and quantification of nitazoxanide based on graphene-polyaniline (Grp-Pani) nanocomposite sensor. Journal of the Electrochemical Society. 2014;161:H1-H6. DOI: 10.1039/C4RA08543D
  11. 11. Gao YS, Xu JK, Lu LM, Wu LP, Zhang KX, Nie T, et al. Overoxidized polypyrrole/graphene nanocomposite with good electrochemical performance as novel electrode material for the detection of adenine and guanine. Biosensors & Bioelectronics. 2014;62:261-267. DOI: 10.1016/j.bios.2014.06.044
  12. 12. Zhang W, Yuan R, Chai YQ , Zhang Y, Chen SH. A simple strategy based on lanthanum-multiwalled carbon nanotube nanocomposites for simultaneous determination of ascorbic acid, dopamine, uric acid and nitrite. Sensors and Actuators B: Chemical. 2012;166-167:601-607. DOI: 10.1016/j.snb.2012.03.018
  13. 13. Mao H, Liang J, Zhang H, Pei Q , Liu D, Wu S, et al. Poly(ionicliquids) functionalized polypyrrole/graphene oxide nanosheets for electrochemical sensor to detect dopamine in the presence of ascorbic acid. Biosensors & Bioelectronics. 2015;70:289-298. DOI: 10.1016/j.bios.2015.03.059
  14. 14. Wang W, Xu G, Cui XT, Sheng G, Luo X. Enhanced catalytic and dopamine sensing properties of electrochemically reduced conducting polymer nanocomposite doped with pure graphene oxide. Biosensors & Bioelectronics. 2014;58:153-156. DOI: 10.1016/j.bios.2014.02.055
  15. 15. Lu L, Zhang O, Xu J, Wen Y, Duan X, Yu H, et al. A facile one-step redox route for the synthesis of graphene/poly(3,4-ethylenedioxythiophene) nanocomposite and their applications in biosensing. Sensors and Actuators B: Chemical. 2013;181:567-574. DOI: 10.1016/j.snb.2013.02.024
  16. 16. Jain R, Shrivastava S. A graphene-polyaniline-Bi2O3 hybrid film sensor for voltammetric quantification of anti-inflammatory drug etodolac. Journal of the Electrochemical Society. 2014;161:H189-H194. DOI: 10.1149/2.043404jes
  17. 17. Xue C, Wang X, Zhu W, Han Q , Zhu C, Hong J, et al. Electrochemical serotonin sensing interface based on double-layered membrane of reduced graphene oxide/polyaniline nanocomposites and molecularly imprinted polymers embedded with gold nanoparticles. Sensors and Actuators B: Chemical. 2014;196:57-63. DOI: 10.1016/j.snb.2014.01.100
  18. 18. Singh K, Solanki PR, Basu T, Malhotra BD. Polypyrrole/multiwalled carbon nanotubes based biosensor for cholesterol estimation. Polymers for Advanced Technologies. 2012;23:1084-1091. DOI: 10.1002/pat.2020
  19. 19. Karadas N, Ozkan SA. Electrochemical preparation of sodium dodecylsulfate doped over-oxidized polypyrrole/multi-walled carbon nanotube composite on glassy carbon electrode and its application on sensitive and selective determination of anticancer drug: Pemetrexed. Talanta. 2014;119:248-254. DOI: 10.1016/j.talanta.2013.10.065
  20. 20. Xu G, Li B, Wang X, Luo X. Electrochemical sensor for nitrobenzene based on carbon paste electrode modified with a poly(3,4-ethylenedioxythiophene) and carbon nanotube nanocomposite. Microchimica Acta. 2014;181:463-469. DOI: 10.1007/s00604-013-1136-y
  21. 21. Wang L, Hua E, Liang M, Ma C, Liu Z, Sheng S, et al. Graphene sheets, polyaniline and AuNPs based DNA sensor for electrochemical determination of BCR/ABL fusion gene with functional hairpin probe. Biosensors & Bioelectronics. 2014;51:201-207. DOI: 10.1016/j.bios.2013.07.049
  22. 22. Yang Y, Zhang S, Kang M, He L, Zhao J, Zhang H, et al. Selective detection of silver ions using mushroom-like polyaniline and gold nanoparticle nanocomposite-based electrochemical DNA sensor. Analytical Biochemistry. 2015;490:7-13. DOI: 10.1016/j.ab.2015.08.010
  23. 23. Spain E, Kojima R, Kaner RB, Wallace GG, Grady JO, Lacey K, et al. High sensitivity DNA detection using gold nanoparticle functionalized polyaniline nanofibres. Biosensors & Bioelectronics. 2011;26:2613-2618. DOI: 10.1016/j.bios.2010.11.017
  24. 24. Singh R, Verma R, Sumana G, Srivastava AK, Sood S, Gupta RK, et al. Nanobiocomposite platform based on polyaniline-iron oxide-carbon nanotubes for bacterial detection. Bioelectrochemistry. 2012;86:30-37. DOI: 10.1016/j.bioelechem.2012.01.005
  25. 25. Saberi RS, Shahrokhian S, Marrazza G. Amplified electrochemical DNA sensor based on polyaniline film and gold nanoparticles. Electroanalysis. 2013;25:1373-1380. DOI: 10.1002/elan.201200434
  26. 26. Wilson J, Radhakrishnan S, Sumathi C, Dharuman V. Polypyrrole-polyaniline- Au (PPy-PANi-Au) nano composite films for label-free electrochemical DNA sensing. Sensors and Actuators B: Chemical. 2012;171-172:216-222. DOI: 10.1016/j.snb.2012.03.019
  27. 27. Radhakrishnan S, Sumathi C, Umar A, Kim SJ, Wilson J, Dharuman V. Polypyrrole-poly(3,4-ethylenedioxythiophene)-Ag (PPy-PEDOT-Ag) nanocomposite films for label-free electrochemical DNA sensing. Biosensors & Bioelectronics. 2013;47:133-140. DOI: 10.1016/j.bios.2013.02.049
  28. 28. Tam PD, Hieu NV. Conducting polymer film-based immunosensors using carbon nanotube/antibodies doped polypyrrole. Applied Surface Science. 2011;257:9817-9824. DOI: 10.1016/j.apsusc.2011.06.028
  29. 29. Truong LTN, Chikae M, Ukita Y, Takamur Y. Labelless impedance immunosensor based on polypyrrole-pyrolecarboxylic acidcopolymer for HCG detection. Talanta. 2011;85:2576-2580. DOI: 10.1016/j.talanta.2011.08.018
  30. 30. Dey A, Kaushik A, Arya SK, Bhansali S. Mediator free highly sensitive polyaniline-gold hybrid nanocomposite based immunosensor for prostatespecific antigen (PSA) detection. Journal of Materials Chemistry. 2012;22:14763-14772. DOI: 10.1039/C2JM31663C
  31. 31. Linting Z, Ruiyi L, Zaijun L, Qianfang X, Yinjun F, Junkang L. An immunosensor for ultrasensitive detection of aflatoxin B1 with an enhanced electrochemical performance based on graphene/conducting polymer/gold nanoparticles/the ionic liquid composite film on modified gold electrode with electrodeposition. Sensors and Actuators B: Chemical. 2012;174:359-365. DOI: 10.1016/j.snb.2012.06.051
  32. 32. Zang S, Liu Y, Lin M, Kang J, Sun Y, Lei H. A dual amplified electrochemical immunosensor for ofloxacin: Polypyrrole film-Au nanocluster as the matrix and multi-enzyme-antibody functionalized gold nanorod as the label. Electrochimica Acta. 2013;90:246-253. DOI: 10.1016/j.electacta.2012.12.021
  33. 33. Ruiyi L, Qianfang X, Zaijun L, Xiulan S, Junkang L. Electrochemical immunosensor for ultrasensitive detection of microcystin-LR based on graphene-gold nanocomposite/functional conducting polymer/goldnanoparticle/ionic liquid composite film with electrodeposition. Biosensors & Bioelectronics. 2013;44:235-240. DOI: 10.1016/j.bios.2013.01.007
  34. 34. Li S, Liu JY, Lian W, Cui M, Xu W, et al. Electrochemical immunosensor based on graphene-polyaniline composites and carboxylated graphene oxide for estradiol detection. Sensors and Actuators B: Chemical. 2013;188:99-105. DOI: 10.1016/j.snb.2013.06.082
  35. 35. Liu PZ, Hu XW, Mao CJ, Niu HL, Song JM, Jin BK, et al. Electrochemiluminescence immunosensor based on graphene oxide nanosheets/polyaniline nanowires/CdSe quantum dots nanocomposites for ultrasensitive determination of human interleukin-6. Electrochimica Acta. 2013;113:176-180. DOI: 10.1016/j.electacta.2013.09.074
  36. 36. Liu K, Zhang J, Liu Q , Huang H. Electrochemical immunosensor for alpha-fetoprotein determination based on ZnSe quantum dots/azure I/gold nanoparticles/poly(3,4-ethylenedioxythiophene) modified Pt electrode. Electrochimica Acta. 2013;114:448-454. DOI: 10.1016/j.electacta.2013.10.018
  37. 37. Li L, Li W, Yang H, Ma C, Yu J, Yan M, et al. Sensitive origami dual-analyte electrochemical immunodevice based on polyaniline/Au-paper electrode and multi-labeled 3D graphene sheets. Electrochimica Acta. 2014;120:102-109. DOI: 10.1016/j.electacta.2013.12.076
  38. 38. Serafin V, Agui L, Yanez Sedeno P, Pingarron JM. Determination of prolactin hormone in serum and urine using an electrochemical immunosensor based on poly(pyrrolepropionicacid)/carbon nanotubes hybrid modified electrodes. Sensors and Actuators B: Chemical. 2014;195:494-499. DOI: 10.1016/j.snb.2014.01.055
  39. 39. Mishra SK, Srivastava AK, Kumar D, Mulchandani A, Rajesh. Protein functionalized Pt nanoparticles-conducting polymer nanocomposite film: Characterization and immunosensor application. Polymer (Guildf.). 2014;55:4003-4011. DOI: 10.1016/j.polymer.2014.05.061
  40. 40. Wang D, Hu W, Xiong Y, Xu Y, Li CM. Multifunctionalized reduced graphene oxide-doped polypyrrole/pyrrolepropylic acid nanocomposite impedimetric immunosensor to ultra-sensitively detect small molecular aflatoxin B1. Biosensors & Bioelectronics. 2015;63:185-189. DOI: 10.1016/j.bios.2014.06.070
  41. 41. Fan H, Guo Z, Gao L, Zhang Y, Fan D, Ji G, et al. Ultrasensitive electrochemical immunosensor for carbohydrate antigen 72-4 based on dual signal amplification strategy of nanoporous gold and polyaniline–Au asymmetric multicomponent nanoparticles. Biosensors & Bioelectronics. 2015;64:51-56. DOI: 10.1016/j.bios.2014.08.043
  42. 42. He S, Wang Q , Yu Y, Shi Q , Zhang L, Chen Z. One-step synthesis of potassium ferricyanide-doped polyaniline nanoparticles for label-free immunosensor. Biosensors & Bioelectronics. 2015;68:462-467. DOI: 10.1016/j.bios.2015.01.018

Written By

Baiju John

Submitted: 14 November 2018 Reviewed: 13 May 2019 Published: 11 March 2020