Silver nanoparticles as a nanoprobe for trace level simultaneous detection of streptomycin sulfate and isoniazid and anti-TB activity of their nanoparticles complexes

•McAgNPs efficiently and simultaneously detect streptomycin sulfate and isoniazid.•Probe was found highly sensitive with limit of detection of 0.044 and 0.045 µM, respectively.•Established assay proved highly selective in the presence of other competing drugs, metals and biological species.•Method was validated by the detection of anti-TB drugs in environmental, biological and pharmaceutical samples.•McAgNPs-Drug complexes inhibited MTB even at lower concentrations as compared to each drug alone. A facile method was developed for the simultaneous detection of two anti-TB drugs (i.e., streptomycin sulfate and isoniazid) by using maltol capped silver nanoparticles (McAgNPs) as a chemosensor. The interaction between anti-TB drugs and McAgNPs depends on aggregation due to the electrostatic interaction and involvement of an amine group in the formation of a drug nanoparticles complex. The colorimetric change from yellow to pink was observed when McAgNPs interact with streptomycin sulfate (STR.SO4) and leads to the surface plasmon resonance (SPR) quenching at 436 nm followed by a red shift at 664 nm. While interaction of isoniazid (INH) with McAgNPs produced a minor change in color intensity (light to dark yellow) with significant enhancement in SPR at 436 nm. A good linear relationship was observed in terms of drug concentrations (i.e., 0.04–100 and 0.1–100 µM), and the limit of detections (i.e., 0.044 and 0.045 µM) for STR.SO4 and INH, respectively. The proposed method was also validated in environmental, biological and pharmaceutical samples with excellent recovery rates. For practical applicability, the combination of McAgNPs with STR.SO4 and INH were successfully tested against Mycobacterium tuberculosis (MTB) sensitive strain (H37Rv). Obtained results showed that McAgNPs-drug complexes inhibited MTB significantly far below the critical concentrations of the drugs. Hence, McAgNPs not only have great potential as a dual sensor but also their complexes with STR.SO4 and INH for TB treatment.