Micro-Engineered Smart ZnO Inverse Opal Electrodes with AgCuS Nanocrystal Amplification for Ultrasensitive Anti-LGI1 Antibody Detections

Micro-fabrication and structural engineering of an ultrasensitive photoelectrochemical (PEC) micro-sensing platform have been developed, based on ZnO inverse opal electrodes with signal amplification enhanced by AgCuS nanocrystals, specifically designed for the detection of anti-LGI1 antibodies. The delayed light effect inherent in the ZnO inverse opal structure enhances photoelectrochemical efficiency by extending the effective optical path. Incorporation of AgCuS nanocrystals significantly augments the photoelectric sensitivity of the ZnO inverse opal, maximizing visible light utilization, accelerating charge transfer kinetics, and substantially enhancing photocurrent generation. Leveraging the uniform porous architecture of the ZnO inverse opal, the ZnO/AgCuS film provides an expansive surface area for biomolecule immobilization and facilitates enhanced electron transport. The ZnO/AgCuS heterogeneous film was innovatively implemented as a PEC bioassay platform. Under optimized conditions, the biosensor exhibited a linear detection range of 0.01–500 ng/mL and a detection limit of 13 pg/mL for Anti-LGI1. Furthermore, the fabricated PEC biosensor demonstrated robust performance in human serum sample analyses, characterized by high repeatability, long-term stability, and excellent specificity. This work proposes a micro-manufacturing strategy for high-performance PEC biodevices, promoting the development of intelligent diagnostic platforms for autoimmune encephalitis.