Chiral ZnO Nanostructures with Chiral-Induced Spin Selectivity-Induced Spin Polarization for Ultrasensitive Photoelectrochemical DNA Detection

Photoelectrochemical sensor-based semiconductor materials have been extensively employed, but the inadequate carrier separation efficiency and the insufficient photoelectric conversion efficiency of such photoelectrochemical materials limit the sensitivity of the sensors. Here, chiral and achiral ZnO have been prepared using chiral and achiral methionines as symmetry-breaking agents. Magnetic force testing using circular polarization spectroscopy and atomic force microscopy has revealed that chiral semiconducting materials can induce spin polarization in conductors when they are used as spin filters. And under the influence of the chiral spin polarization effect, the fluorescence lifetime of chiral ZnO was extended to 11 μs, which was 1.2 times that of nonchiral ZnO. The photocurrent signal is three times that of nonchiral ZnO. After the introduction of ZnS, it forms a heterojunction with ZnO, which further increases the photocurrent signal. Under optimal conditions, this sensor demonstrated a detection range of 10 –2 to 10 5 pM and a detection threshold of 4.42 fM for target DNA. A new approach to various biological research and early disease diagnosis is provided by its high sensitivity and excellent stability.