Electrodes Based on PEDOT Nanotubes Decorated with Gold Nanoparticles for Biosensing and Energy Storage

Abstract

Poly­(3,4-ethylenedioxythiophene) nanotubes (PEDOT-NTs) were electrochemically synthesized onto a stainless steel mesh electrode followed by one-pot electrodeposition of gold nanoparticles (AuNPs) at the nanotubular surface. The hybrid nanomaterial has shown remarkable electrochemical properties with the diminishment of the charge transfer resistance besides the possibility of further electrode modification by the thiol bonding at the AuNPs. The modified electrodes were deeply characterized by electrochemical techniques, in special by electrochemical impedance spectroscopy, which provides valuable information about the interfacial processes. The morphology of the nanomaterial was characterized by scanning electron microscopy and transmission electron microscopy images. The biosensing properties were evaluated through the avidin/biotin pair. The methodology of construction of the biosensor was further adapted to explore a cancer biomarker detection, the folate binding protein (FBP), which presented high sensitivity with a limit of detection of 4.5 pmol L–1, one of the lowest found in literature. Also, the hybrid material was used in the development of supercapacitors, the inclusion of AuNPs provided a remarkable durability of the PEDOT-NTs modified electrodes presenting long cycling stability (over 3000 cycles) and high energy density, compared with bare PEDOT nanotubes modified electrodes.

Development of Folate-Group Impedimetric Biosensor Based on Polypyrrole Nanotubes Decorated with Gold Nanoparticles

“…Folic Acid has a great affinity for FBP, and the impedimetric response is found in Figure 6 , in the concentration range from 0.02 up to 113.3 nmol L −1 , in triplicate. The analytical curve was inserted; the limit of detection (LOD) was calculated as 0.030 nmol L −1 , and the limit of quantification (LOQ) was 0.090 nmol L −1 , indicating that the proposed biosensor herein can detect and quantify the range of concentration of clinical interest, which is around 11 up to 34 nmol L −1 [ 24 , 25 ]. As this biomarker can be found as a group of molecules, many different configurations of biosensors based on folate can be found in the literature, and the simple comparison between analytical parameters is not always easy to study.…”

“…The interaction between FA and FR-α has a high specificity (KD = 10 −9 mol L −1 ), so this strong interaction can be explored for the biosensor transduction mechanism. Recent studies indicate that the normal levels of FA in the human serum are around 11.3–34.0 nmol L −1 , emphasizing the need for a highly sensitive biosensor [ 24 , 25 ]. In this study, we developed a hybrid nanomaterial formed by polypyrrole nanotubes and gold nanoparticles, electrochemically synthesized in a rapid and straightforward methodology.…”

Development of polypyrrole (nano)structures decorated with gold nanoparticles toward immunosensing for COVID-19 serological diagnosis

“…For biosensor construction[ 16 ]: (a) The gold nanoparticle surface functionalization was performed by dipping the synthesized electrode into an MPA (1 mmol L -1 ) freshly prepared aqueous solution for at least 12 h. The use of water was due to the high solubility of PPy in ethanol, which could be removed from the electrode surface. After this step, the electrode was carefully washed with water.…”

“…Different polymer morphologies, such as nanoarchitectures, are able to offer material properties improvement, including a higher electroactive area and facilitated charge-transfer process, thus offering higher sensitivity, good recovery and a fast response in sensing applications [ 8 , 15 ]. Also, the association with gold nanoparticles (AuNPs) can improve even more the CPs’ stability, biocompatibility, sensitivity, and selectivity, making this strategy very appealing for new COVID-19 biosensors applied as new tools for diagnosis [ 11 , 16 ].…”

In situ engineering of Au–Ag alloy embedded PEDOT nanohybrids at a solvent/non-solvent interface for the electrochemical enzyme-free detection of histamine

“…Monitoring of clinical biomarkers could be deemed of enormous importance, as they can provide critical input regarding an individual's health conditions and may assist in managing diseases and preventing mortalities. 1 Histamine (2-(1Himidazol-4-yl)ethanamine) (HA) is one such vasoactive amine that acts as a mediator in both physiological and pathological processes. 2,3 In particular, it performs a dual role as a neurotransmitter and neuromodulator, regulating the release of other neurotransmitters.…”