Co-doped Bi2MoO6 lattice distortion strategy-based photoelectrochemical sensors for highly sensitive detection of profenofos residues in milk and cabbage

Pesticide residues in food pose significant risks to human health, necessitating accurate monitoring methods. To address this, a lattice distortion strategy-based highly sensitive photoelectrochemical (PEC) sensor was developed for profenofos (PFF) detection. Substitution of Bi^3 + with Co²⁺ in the Bi₂MoO₆ lattice induced enhanced lattice distortions and oxygen vacancies, reducing the bandgap and dramatically improving visible-light absorption and charge transfer efficiency. These modifications synergistically boosted PEC performance, with 4 % Co-doped Bi₂MoO₆ achieving optimal results, including a reduced narrowed bandgap (2.28 eV) and a significantly enhanced photocurrent density compared to pristine Bi₂MoO₆. The sensor exhibited a broad linear detection range (0.5 mg L⁻¹ to 0.01 ng L⁻¹) and an ultralow detection limit of 3.3 pg L⁻¹, demonstrating excellent sensitivity and selectivity in real food samples. This work presents an innovative efficient, non-toxic, and eco-friendly tool for pesticide residue detection, paving new avenues for food safety monitoring and public health protection.