Abstract
In this research, we developed electrochemical biosensor which was composed of hemoglobin (Hb)-DNA conjugate on nanoporous gold thin film (NPGF) for hydrogen peroxide (H2O2) detection. For the first time, Hb and DNA was conjugated as a sensing platform for uniform orientation of Hb on electrode. The newly developed Hb-DNA conjugate was designed to prevent Hb from aggregation on electrode. DNA hybridization of Hb-DNA conjugate and complementary DNA (cDNA) on NPGF electrode induced uniformly assembled biosensor. Furthermore, NPGF electrode fabrication method was introduced to the increment of the surface area. To confirm the conjugation of Hb-DNA conjugate, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and ultraviolet–visible spectroscopy (UV–VIS) were used. Formation of the NPGF electrode was verified by scanning electron microscope (SEM). Atomic force microscopy (AFM) was operated for the confirmation of Hb-DNA immobilization on electrode. The electrochemical property of fabricated electrode was investigated by cyclic voltammetry (CV). Also, H2O2 sensing performance of fabricated electrode was investigated by amperometric i-t curve technique. This sensor showed a wide linear range from 0.00025 to 5.00 mM and a correlation coefficient of R2 = 0.9986. The detection limit was 250 nM. Proposed biosensor can be utilized as a sensing platform for development of biosensor.
Highlights
Over the past decades, various researches for the development of biosensors have received the huge interests for biomedical and environmental applications
4 Conclusions In the present study, an electrochemical biosensor composed of Hb-DNA conjugate on the nanoporous gold thin film (NPGF) was fabricated for H2O2 detection with electrochemical signal enhancement and selectivity
The NPGF electrode fabricated by electrodeposition technique was used to extend the surface area of the electrode for electrochemical signal enhancement
Summary
Various researches for the development of biosensors have received the huge interests for biomedical and environmental applications. Several biomolecules such as protein and DNA have some advantages for the development of biosensors including fast response reaction and remarkable selectivity [1, 2]. Metalloproteins have been evaluated as suitable materials for biosensors because of the direct redox properties and the fast electrochemical response [3–5]. As a main by-product of enzymatic reactions, concentration of H2O2 is considered as a parameter for activity coefficient of physiological reactions [11]. Various types of biosensors have been developed to detect H2O2 [12, 13]. Kauffmann’s group developed the H2O2 biosensor using enzyme horseradish peroxidase (HRP) entrapped in a polypyrrole electrode [14]. Luo’s group fabricated H 2O2 biosensor which was based on cytochrome c [15]
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