Ultra-sensitive self-powered sensor based on the hollow Rubik's cube substrate and multiple signal amplification strategy for real-time heavy metal detection.

As a common heavy metal pollutants, lead ion (Pb2+) content monitoring has always been the focus of environmental protection. The rapid development of self-powered electrochemical biosensors open up the broad application prospects for Pb2+ detection. In this work, we innovatively design three-dimensional (3D) hollow cube bimetallic sulfide heterojunction microparticles combine with DNAzyme functional nucleic acid mediated by hybridization chain reaction (HCR) strategy to construct the ultra-sensitive self-powered sensor. The multiple amplification technology synergically enhanced the sensitivity. The electrochemical data show that the sensor has a wide linear response in the range of 0.0010–25 ng·mL−1 with the low detection limit is 3.10 pg·mL−1 (S / N = 3). The most special feature is that the introduction of commercial smart phone APP can effectively reduce cost, simplify process, and realize rapid on-site detection. In conclusion, the work can provide a feasible strategy for monitoring other hazardous substances, and advance the determination of environmental pollutants in the field. • High-performance electrochemical sensor achieves sensitive detection of heavy metal ions. • Hollow cube structure increases the specific surface area and enhances catalytic activity. • Commercial app contribute to on-site detection and has strong practical significance. [ABSTRACT FROM AUTHOR]