Synthesis, Characterisation of Novel Polyaniline Nanomaterials and Application in Amperometric Biosensors

Abstract

Summary: Anthracene sulfonic acid doped polyaniline nanomaterials were prepared through the chemical oxidative polymerisation process. Ammonium peroxydisulfate (APS) was employed as oxidant. Scanning electron microscopy (SEM) results show the resultant polyaniline (PANi) materials exhibited nanofibrillar morphology with diameter sizes less than 300 nm. Using the nanofibrillar PANI, amperometric biosensors for H2O2 and erythromycin were constructed through the drop‐coating technique. Anthracene sulfonic acid (ASA) doped PANi and the test enzymes horseradish peroxidase, (HRP), or cytochrome P450 3A4, (CYP4503A4) were mixed in phosphate buffer solution before drop coating onto the electrode. The resultant biosensors displayed typical Michaelis‐Menten behaviour. The apparent Michaelis‐Menten constant obtained was 0.18 ± 0.01 mM and 0.80 ± 0.02 µM L−1 for the peroxide and erythromycin biosensor respectively. The sensitivity for the peroxide sensor was 3.3 × 10−3 A · cm−2 · mM−1, and the detection limit was found to be 1.2 × 10−2 mM respectively. Similarly, the sensitivity for the erythromycin sensor was in the same order at 1.57 × 10−3 A · cm−2 · mM−1 and detection limit was found to be 7.58 × 10−2 µM.

Mercaptobenzothiazole-on-Gold Organic Phase Biosensor Systems: 3. Thick-Film Biosensors for Organophosphate and Carbamate Pesticide Determination

“…The platinum (Pt) counter electrode was regularly cleaned before and after synthesis and in between synthesis and analysis. This involved flaming the Pt electrode in a Bunsen burner until it was white hot, followed by rinsing with copious quantities of deionised water (Michira et al, 2007;Somerset et al, 2007).…”

Polyaniline-based biosensors

“…In particular, electrochemical biosensors using peroxidase-modified electrodes (MEs) emerged as a promising choice by virtue of the intrinsic advantages Chemically synthesized anthracene doped PANI nanofibers (PANI-NF, 300 nm) were employed to immobilize HRP and then to investigate their biosensing response studies. 14 To enhance the electrocatalytic behavior of PANI, metal nanoparticles were explored as the electron tunnelling centers and thus toward the development of highly sensitive thirdgeneration mediator-less biosensors. In this regard, Bao et al 15 have utilized a green approach to fabricate polyaniline nanotubes (PANI-NT)/gold nanoparticles (AuNPs) hybrid nanostructures utilizing electrospun polyacrylonitrile (PAN) nanofibers as the sacrificial templates.…”

Enzyme‐Based Biosensors: Synthesis and Applications

“…For this purpose, PANI is considered to be an attractive biosensor polymer because such electronic material exhibits two redox couples in the right potential range to facilitate an enzymepolymer charge transfer. Therefore, PANI is one of the most widely used biosensor carriers due to its good environmental stability and the fact that its electrical properties can easily be tuned through dopant inclusion/exclusion principles, and it has found a variety of uses in biosensor technology, electrochromic devices, energy storage systems, and anticorrosion materials [104] . Doped PANI, however, is diffi cult, brittle, and insoluble in common organic solvents, making its largescale processability diffi cult.The insolubility/infusibility of PANI is related to its rigid π -π conjugation effect [104] .…”

“…Therefore, PANI is one of the most widely used biosensor carriers due to its good environmental stability and the fact that its electrical properties can easily be tuned through dopant inclusion/exclusion principles, and it has found a variety of uses in biosensor technology, electrochromic devices, energy storage systems, and anticorrosion materials [104] . Doped PANI, however, is diffi cult, brittle, and insoluble in common organic solvents, making its largescale processability diffi cult.The insolubility/infusibility of PANI is related to its rigid π -π conjugation effect [104] . In addition, the monomer aniline is a carcinogen and also must be distilled prior to use [105] .…”

“…In addition, the monomer aniline is a carcinogen and also must be distilled prior to use [105] . As a result, its large -scale applicability has been challenged by its poor thermal stability and diffi cult processability [104,105] . For these, considerable efforts have been undertaken to face up to the challenge in order to overcome PANI organic and inorganic insolubility problems.…”