Development of a sensitive electrochemical immunosensor using polyaniline functionalized graphene quantum dots for detecting a depression marker.
As a new type of conductive material, polyaniline functionalized graphene quantum dots (PAGD), which were prepared by in-situ polymerization had been used to construct a novel electrochemical immunosensor for early screening of depression markers-heat shock protein 70 (HSP70). Profiting from the huge specific surface area, good bioactivity and excellent structure of PAGD, a variety of heat shock protein 70 (HSP70) was firmly loaded on the surface of PAGD for successful construction of basic electrode (HSP70/PAGD/GCE), which was characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), respectively. Due to the HSP70 fixed on the surface of basic electrode and the HSP70 in the samples can competitively combine with the horseradish peroxidase labeled human HSP70 antibody (HRP-Strept-Biotin-Ab). As a result, there is negative correlation between the concentration of HSP70 in samples and the detection signal of the proposed electrochemical immunosensor (HRP-Strept-Biotin-Ab-HSP70/PAGD/GCE) in the test liquid. Under conditions optimized for determining HSP70, wide linearity was obtained in the range of 0.0976-100 ng/mL, with a low detection limit of 0.05 ng/mL at 3σ. Moreover, the proposed electrochemical immunosensors was successfully applied to detect HSP70 in plasma samples, and exhibited good precision, acceptable stability and reproducibility. Therefore, this study provides a novel and convenient method for early clinical screening of depression markers, and also provides a reliable and objective analysis method for the diagnosis of depression at the molecular level.
['Sun|Bolu|B|', 'Wang|Yanping|Y|', 'Li|Dai|D|', 'Li|Wuyan|W|', 'Gou|Xiaodan|X|', 'Gou|Yuqiang|Y|', 'Hu|Fangdi|F|']
D000328:Adult D000814:Aniline Compounds D015415:Biomarkers D015374:Biosensing Techniques D002244:Carbon D003863:Depression D058266:Dielectric Spectroscopy D055664:Electrochemical Techniques D004566:Electrodes D005898:Glass D006108:Graphite D006801:Humans D045663:Quantum Dots D015203:Reproducibility of Results
Immunosensor Polyaniline Graphene quantum dots Depression markers