Heparin-platinum nanozymes with enhanced oxidase-like activity for the colorimetric sensing of isoniazid

• Published in: Talanta (Oxford) 2020-05, Vol.211, p.120707-120707, Article 120707
• Main Authors: He, Shao-Bin, Yang, Liu, Lin, Xiu-Ling, Chen, Li-Ming, Peng, Hua-Ping, Deng, Hao-Hua, Xia, Xing-Hua, Chen, Wei
• Format: Article
• Language: English
• Subjects: Colorimetric sensor; Drug tablet; Isoniazid; Nanozyme; Oxidase-like activity; Platinum nanoparticles
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2019.120707

In this study, a colorimetric sensing assay of isoniazid based on excellent oxidase-like activity of heparin sodium stabilized platinum nanoparticles (HS-PtNPs) has been demonstrated. The newly prepared HS-PtNPs exhibit a great dispersion with an average size distribution of 4.8 ± 0.6 nm, and maintain more than 90% catalytic activity under strong acid and alkali or long-term storage conditions, indicating a robust nanomaterial with attractive potential. The HS-PtNPs show distinct oxidase-like activity with an ultrahigh affinity (Km = 0.01012 mM) for 3, 3′, 5, 5′-tetramethylbenzidine (TMB). More significantly, we found that the pyridine ring of isoniazid has a strong reductive hydrazyl substitution, which can compete with TMB for the catalytic site of HS-PtNPs resulting in a colorless solution. Accordingly, a colorimetric sensing of isoniazid was fabricated. A linear relationship for isoniazid was achieved in 2.5 × 10−6 to 2.5 × 10−4 M (R2 = 0.998) with a low limit of detection 1.7 × 10−6 M (S/N = 3). Recovery experiments in drug tablets show that the standard recovery rates were 95%–103%. The quantitative detection data for isoniazid in drug tablets calculated respectively from the standard method and this method exhibited a high correlation coefficient (a slope of 0.9995), suggesting that high accuracy in isoniazid detection. [Display omitted] •Heparin-capped Pt nanozyme was first synthesized by a facile reduction method.•Heparin-capped Pt nanozyme offers enhanced oxidase-like activity.•Isoniazid competes with TMB for the catalytic site of Pt nanozyme.•Colorimetric sensor for isoniazid was realized.