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 Ti 3 C 2 /Bi/BiOI, which was built from Ti 3 C 2 nanosheets and Bi/BiOI microspheres. Photoelectrochemical (PEC) sensors based on Ti 3 C 2 /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/Ti 3 C 2 /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/Ti 3 C 2 /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.