Rational design of PtCu nanopyramid interfaces for aggregation-induced gold deposition and ultra-sensitive detection of zearalenone

In this work, we developed a morphology-engineered platinum-copper triangular nanopyramid (PtCu TNP) probe and integrated it into a lateral flow immunoassay (LFIA) for the rapid detection of zearalenone (ZEN) in corn. Distinct from conventional LFIA probes, this study introduces a unique PtCu TNP-mediated in-situ gold deposition mechanism that enables catalytic, self-driven signal reinforcement at the test line, markedly enhancing optical intensity through aggregation-driven growth. The PtCu TNPs were synthesized via a simple and efficient route, yielding well-defined multibranched architectures with high catalytic activity and binding stability. Under optimized conditions, the Au@PtCu TNPs-LFIA achieved a detection limit of 0.13 ng/mL-about 1-2 times lower than conventional colloidal-gold LFIAs-and expanded the dynamic range to 0.13-15.5 ng/mL. Moreover, comparable signal intensity was obtained using only 25 % of the probe amount, demonstrating enhanced sensitivity, reduced reagent consumption, and excellent quantitative performance. Successful validation in fortified corn samples highlights the potential of this low-cost, high-efficiency immunochromatographic platform for practical food-safety monitoring.