Photoelectrochemical sensing of isoniazid and streptomycin based on metal Bi-doped BiOI microspheres grown on book-shape layers of Ti₃C₂ heterostructures

Isoniazid and streptomycin are vital drugs for treating tuberculosis, which are utilized as efficient anti-tuberculosis agents. This paper presents a novel visible-light-driven composite photocatalyst Ti₃C₂/Bi/BiOI, which was built from Ti₃C₂ nanosheets and Bi/BiOI microspheres. Photoelectrochemical (PEC) sensors based on Ti₃C₂/Bi/BiOI were synthesized for isoniazid identification, which showed a linear concentration range of 0.1–125 μM with a detection limit of 0.05 μM (S/N = 3). Moreover, we designed a PEC aptasensors based on aptamer/Ti₃C₂/Bi/BiOI to detect streptomycin in 0.1 M PBS covering the electron donor isoniazid, because the isoniazid consumes photogenerated holes thus increasing the photocurrent effectively and preventing photogenerated electron–hole pairs from being recombined. Furthermore, PEC aptasensors based on aptamer/Ti₃C₂/Bi/BiOI were synthesized for streptomycin identification, which exhibited a linear concentration range of 0.01–1000 nM with a detection limit of 2.3 × 10^-3 nM (S/N = 3), and are well stable in streptomycin sensing.