Silver Nanoparticles Decorated Polyaniline Nanowires-Based Electrochemical DNA Sensor: Two-step Electrochemical Synthesis

Abstract

In this work, silver nanoparticles decorated onto polyaniline nanowires were synthesized site-specifically onto Pt working electrodes (with only 0.8 mm2 area) using a novel, rapid, and effective electrochemical procedure: electropolymerization of PANi NWs and electrodeposition of AgNPs. The complementary properties of PANi NWs and AgNPs were obtained, including high surface area, high electrochemical activity, high biocompatibility, high chemical stability and good adhesion with the electrode surface. Obtained results showed advantages of the electrosynthesis method compared to traditional methods, which have difficulties in binding between modifying materials with electrode surfaces. The sensor surface modification with the PANi NWs/AgNPs material facilitated the probe DNA immobilization and improved the electrochemical signal of the DNA sensors. The detection limit of the sensors was 2.80 × 10−15 M. The DNA sensors exhibited advantages including direct detection, high sensitivity, good specificity, and potential miniaturization for development of lab-on-a-chip systems.

Electrochemical DNA Sensor Based on Poly(Azure A) Obtained from the Buffer Saturated with Chloroform

“…For this reason, monitoring of the redox activity of the polymers shows high sensitivity toward specific DNA interactions. Thus, DNA sensors based on polyaniline [ 30 , 31 , 32 , 33 , 34 ], polypyrrole [ 35 , 36 , 37 ], polythionine [ 38 ], and poly(neutral red) [ 15 , 39 ] have been described and successfully used for the determination of intercalation, DNA damage, and detection of hybridization with complementary DNA sequences. It should be noted that application of such modifiers frequently limits the measurement conditions by pH region required for redox signal recording (polyaniline) or by interference with reactive species able to react with electrodes near the redox activity of appropriate polymers (polyphenothiazines).…”

Multi-walled Carbon Nanotubes/Manganese Dioxide Nano- flowers-like/Polyaniline Nanowires Nanocomposite Modified Electrode: A New Platform for a Highly Sensitive Electrochemical Impedance DNA Sensor

“…In recent decades, conducting polymers have been attracted the much attention of scientists worldwide for biosensing applications thanks to their unique properties [1][2][3][4]. Pure conducting polymers are formed in various structures such as nanowires, nanotubes and nano-thin films to obtain a large surface area and a high efficiency [5,6].…”

“…In general, these nanocomposites can be synthesized by different techniques including chemical, electrochemical, photochemical and mechano-chemical methods and these developed materials have been applied for many applications such as energy storage, electrochemical biosensors, electrochemical sensors, FET-based biosensors, and coating and metal protecting [1]. To apply of the inorganic nanomaterial/conducting polymer nanocomposites for development of electrochemical biosensors, these fabricated nanomaterials have to be coated onto the electrodes using a drop-casting and/or an electrochemical method insitu on the working electrode [2,23]. In which, the electrochemical techniques are often used due to well controlling and high reproducibility.…”

“…In which, the electrochemical techniques are often used due to well controlling and high reproducibility. For examples, several PANi nanocomposites-based sensitive electrochemical DNA sensors have been developed such as PANi-graphene nanocomposite [24], silver nanoparticles decorated PANi nanowires [2], carbon dot/ZnO nanorod/PANi composite [25], PANi/gold nanoparticles [26], Sm2O3 NPs-rGO/PANi composite [27]. These developed PANi-based electrochemical DNA sensors have shown sensitivity at nM to fM level for DNA detection, however, the fabrication steps are still laborious.…”

A Flexible DNA Biosensor for Breast Cancer Marker BRCA1 Detection

“…In recent years, AgNWs-based conductive films as a flexible electrode have been developed to replace GCE electrodes, which have attracted great attention due to their prompt and rapid detection. [15][16][17] In this work, AgNWs-decorated polyethylene terephthalate (AgNWs/PET) films were used as a highly bendable and conductive electrode to develop a new electrochemical biosensor for detecting breast cancer gene BRCA1 (Scheme 1). With a high aspect ratio, AgNWs distributed in the PET film could easily form a conductive network that acted as a flexible electrode.…”