Plasmon enhanced broadband photoelectrochemical response of ZnO/CdTe/Bi nanoarrays for quantitative analysis of nasopharyngeal carcinoma in a recyclable microfluidic biosensing chip.

Traction and quantitative detection of trace amount of target cells inside of biochip system in real-time has been a challenge for biomedical and clinical researchers. In this manuscript, we report fabrication of a photoelectrochemical platform that has integrated both biometric recognition and signal acquisition through microfabrication technology. In this chip, a ternary ZnO/CdTe/Bi nanorod array is fabricated, which significantly extends the absorption wavelength from the UV to the visible and even near-infrared regions for both photocarrier generation and surface plasmon resonance, ultimately achieving the amplification of initial photocurrent responses. The artificially designed aptamers with amino groups are assembled on the surface of the outermost Bi nanoparticles, which are used as signal probes due to the specific recognition to the nasopharyngeal carcinoma 5-8F cell. We demonstrate that different concentration of 5-8F cells is captured by aptamers, and the signal changes accordingly with the amount of the cells that have been trapped. As a result, the proposed biochip demonstrates rapid response in a wide linear range of 102-107 cells·mL-1 with the detection limit as low as 32 cells·mL-1 and provides a potential useful model for a variety of biological analysis including clinical point-of-care testing.