Abstract：
Nitrite ions (NO2-), as one of the leading type-A inorganic-anion, showing significant-effects in the aquatic environment and also to humans health. Whereas, the higher uptake causes detrimental threat to human health leading to various chronic diseases, thus demanding efficient, reliable and convenient method for its monitoring. For this purpose, in the present research study we have fabricated the mimetic nonozyme like catalyst based colorimetric nitrite sensor. The acetic acid capped Zinc Oxide (ZnO) nanosheets (NSs) were introduce as per-oxidase mimetic like catalyst which shows high efficiency towards the oxidative catalysis of colorless tetramethylbenzidine (TMB) to oxidized-TMB (blue color) in the presence of Hydrogen-peroxide (H2O2). The present nitrite ions will stimulate the as formed oxidized-TMB (TMBox), and will caused diazotization reaction (diazotized-TMBox), which will not only decreases the peak intensity of UV-visible peak of TMBox at 652 nm but will also produces another peak at 446 nm called as diazotized-TMBox peak, proving the catalytic reaction between the nitrite ions and TMBox. Further, the prepared colorimetric sensor exhibits better sensitivity with a wider range of concentration (1 × 10-3-4.50 × 10-1 µM), lowest limit of detection (LOD) of 0.22 ± 0.05 nM and small limit of quantification (LOQ) 0.78 ± 0.05 nM having R2 value of 0.998. Further, the colorimetric sensor also manifest strong selectivity towards NO2- as compared to other interference in drinking water system. Resultantly, the prepared sensor with outstanding repeatability, stability, reproducibility, re-usability and its practicability in real water samples also exploit its diverse applications in food safety supervision and environmental monitoring.
摘要：
亚硝酸根离子(NO2-),作为主要的A型无机阴离子之一，对水生环境和人类健康都有显著影响。然而,较高的摄入量对人类健康造成有害威胁，导致各种慢性疾病，因此要求高效，可靠、方便的监测方法。为此,在本研究中，我们制造了基于亚硝酸盐比色传感器的模拟非酶样催化剂。引入乙酸封端的氧化锌（ZnO）纳米片（NSs）作为过氧化酶模拟物类似催化剂，在过氧化氢（H2O2）的存在下，其对无色四甲基联苯胺（TMB）至氧化TMB（蓝色）的氧化催化显示出高效率。当前的亚硝酸根离子将刺激所形成的氧化TMB（TMBox），会引起重氮化反应(重氮化-TMBox)，这不仅会降低TMBox在652nm处的紫外可见峰的峰强度，而且还会在446nm处产生另一个称为重氮化TMBox峰的峰，证明了亚硝酸根离子和TMBox之间的催化反应。Further,制备的比色传感器具有较宽的浓度范围（1×10-3-4.50×10-1µM），最低检测限(LOD)为0.22±0.05nM,小定量限(LOQ)为0.78±0.05nM,R2值为0.998。Further,与饮用水系统中的其他干扰相比，比色传感器对NO2-也表现出很强的选择性。结果，制备的传感器具有出色的可重复性，稳定性,再现性，可重复使用性及其在实际水样中的实用性也利用了其在食品安全监管和环境监测中的多种应用。
