Hollow double shell Prussian blue analogue@Au nanocubes with enhanced peroxidase-like activity for isoniazid detection in human serum

Overuse of the anti-tuberculosis drug isoniazid (INH) would cause serious damage to human health. Currently, commonly used analytical methods such as high-performance liquid chromatography, liquid chromatography/mass spectrometry, etc. often rely on large instruments and are difficult to achieve rapid INH detection. Herein, we established an efficient colorimetric method for detecting INH in human serum based on a novel Au-doped hollow double-shell Prussian blue analogue (Mn-PBA-DSNB@Au), which could be prepared through a series of simple co-precipitation, etching, and in-stiu reduction procedures. Due to the high specific surface area and multiple active sites of the hollow structure, the obtained Mn-PBA-DSNB@Au exhibits enhanced peroxidase-like activity, realizing the rapid oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) to blue oxTMB in the presence of hydrogen peroxide, producing a strong absorption at 652 nm. Based on the inhibitory effect of the reducing hydrazide group in INH upon the TMB colorimetric reaction, we constructed a sensitive colorimetric sensing platform for the determination of INH around Mn-PBA-DSNB@Au nanozymes. The developed INH sensor exhibited a linear range of 2–40 μM with a low detection limit of 0.835 μM. Furthermore, it could be extended to the actual detection of real human blood samples, achieving a recovery rate of 101.2 %–102.2 % with <2.6 % RSD.