Quantification of DNA by a Thermal-Durable Biosensor Modified with Conductive Poly(3,4-ethylenedioxythiophene)

Abstract

The general clinical procedure for viral DNA detection or gene mutation diagnosis following polymerase chain reaction (PCR) often involves gel electrophoresis and DNA sequencing, which is usually time-consuming. In this study, we have proposed a facile strategy to construct a DNA biosensor, in which the platinum electrode was modified with a dual-film of electrochemically synthesized poly(3,4-ethylenedioxythiophene) (PEDOT) resulting in immobilized gold nanoparticles, with the gold nanoparticles easily immobilized in a uniform distribution. The DNA probe labeled with a SH group was then assembled to the fabricated electrode and employed to capture the target DNA based on the complementary sequence. The hybridization efficiency was evaluated with differential pulse voltammetry (DPV) in the presence of daunorubicin hydrochloride. Our results demonstrated that the peak current in DPV exhibited a linear correlation the concentration of target DNA that was complementary to the probe DNA. Moreover, the electrode could be reused by heating denaturation and re-hybridization, which only brought slight signal decay. In addition, the addition of the oxidized form of nicotinamide adenine dinucleotide (NAD+) could dramatically enhance the sensitivity by more than 5.45-fold, and the limit-of-detection reached about 100 pM.

Fabrication of an Extremely Cheap Poly(3,4-ethylenedioxythiophene) Modified Pencil Lead Electrode for Effective Hydroquinone Sensing

“…It has been reported that the PEDOT coated on the platinum electrode might be the best candidate for the electrochemical detection of hydroquinone due to its intrinsic capability for electron transfer [ 37 ]. However, we have demonstrated that the direct coating of electrochemically synthesized PEDOT film on the Pt electrode often leads to film crack during multiple measurements [ 31 , 33 ]. In this study, we successfully modified a pencil lead (PL) electrode with the electrochemically synthesized PEDOT film.…”

“…Reproducibility is always the main challenge in developing rGO-based electrochemical sensors [ 58 , 60 , 61 ]. On the other hand, there are abundant sulfur atoms in a PEDOT molecular structure that are ready for the stable immobilization of golden nanoparticles, which can then immobilize a variety of biomolecules with thiol groups (-SH) to construct various biosensors [ 31 , 32 , 33 ]. Modification of a platinum electrode with the conductive PEDOT film has also been reported to effectively eliminate the evitable hydrogen ion reduction or water oxidation at slightly negative or positive potentials [ 33 ], and to improve the sensitivity of a biosensor [ 32 , 34 , 35 , 36 ].…”

“…Previously, we have also demonstrated that modification of a platinum electrode with the conductive PEDOT film could effectively eliminate the hydrogen ion reduction and water oxidation at slightly negative or positive potentials [33], which provided limited background interference for a sensitive detection [32,[34][35][36].…”

“…Generally, PEDOT film is facilely fabricated on an electrode with an electrochemical procedure, and its well-defined surface morphology is suitable for the immobilization of biomolecules. In particular, the sulfur atoms in the PEDOT molecular structure open up the opportunity to stably capture the golden nanoparticles, which are able to immobilize a variety of biomolecules with thiol groups (-SH), such as proteins and nucleotides, to construct various biosensors [ 31 , 32 , 33 ]. Previously, we have also demonstrated that modification of a platinum electrode with the conductive PEDOT film could effectively eliminate the hydrogen ion reduction and water oxidation at slightly negative or positive potentials [ 33 ], which provided limited background interference for a sensitive detection [ 32 , 34 , 35 , 36 ].…”

“…Generally, PEDOT film is facilely fabricated on an electrode with an electrochemical procedure, and its well-defined surface morphology is suitable for the immobilization of biomolecules. In particular, the sulfur atoms in the PEDOT molecular structure open up the opportunity to stably capture the golden nanoparticles, which are able to immobilize a variety of biomolecules with thiol groups (-SH), such as proteins and nucleotides, to construct various biosensors [31][32][33].…”