Development of CdSe⁻ZnO Flower-Rod Core-Shell Structure Based Photoelectrochemical Biosensor for Detection of Norovirous RNA.

In this work, the CdSe⁻ZnO flower-rod core-shell structure (CSZFRs) was prepared by ion-exchange method. The surface of CSZFRs was modified by 3-mercaptopropionic acid (MPA), and then the DNA probe was immobilized on the surface via chemical bond between -NH₂ of DNA probe and -COOH of MPA. Finally, the target norovirous (NV) RNA was combined with the probe according to the principle of complementary base pairing, resulting in a decrease of the photocurrent. The results show that the absorbance spectrum of visible light is enhanced for CSZFRs compared with pure ZnO. Under visible light irradiation, the photocurrent of CSZFRs is up to 0.1 mA, which can improve the sensitivity of the photoelectrochemical (PEC) biosensor. In the measurement range of 0⁻5.10 nM, the measured concentrations (c) have a good linear relationship with the output photocurrent of the biosensor. The linear regression equation is expressed as I = 0.03256 - 0.0033c (R² = 0.99, S/N = 3) with a detection limit of 0.50 nM. Therefore, this work realizes a rapid and sensitive method for the detection of NV RNA.