Antibiotic resistance, encoded via particular genes, has become a major global health threat and substantial burden on healthcare. Hence, the facile, low-cost, and precise detection of antibiotic resistance genes (ARGs) is crucial in the realm of human health and safety, especially multiplex sensing assays. Here, a smart pH-regulated switchable photoelectrochemical (PEC) bioassay has been created for ultrasensitive detection of two typical subtypes of penicillin resistance genes bla-CTX-M-1 (target 1, labeled as TDNA1) and bla-TEM (target 2, la...