Zhang Xuan, Hao Nan, Liu Shucheng, Wei Kai, Ma Changchang, Pan Jianming, Feng Sheng
School of Environmental Science and Engineering, Changzhou University, Jiangsu 213164, China.
School of Chemistry and Chemical Engineering, Nanjing University of Information Science &Technology 211800, China.
Talanta. 2024 Sep 1;277:126434. doi: 10.1016/j.talanta.2024.126434. Epub 2024 Jun 14.
Methyl paraoxon (MP) is a highly toxic, efficient and broad-spectrum organophosphorus pesticide, which poses significant risks to ecological environment and human health. Many detection methods for MP are based on the enzyme catalytic or inhibition effect. But natural biological enzymes are relatively expensive and easy to be inactivated with a short service life. As a unique tool of nanotechnology with enzyme-like characteristics, nanozyme has attracted increasing concern. However, a large proportion of nanozymes lack the intrinsic specificity, becoming a main barrier of constraining their use in biochemical analysis. Here, we use a one-pot reverse microemulsion polymerization combine the gold nanoclusters (AuNCs) with molecularly imprinted polymers (MIPs), polydopamine (PDA) and hollow CeO nanospheres to synthesize the bright red-orange fluorescence probe (CeO@PDA@AuNCs-MIPs) with high phosphatase-like activity for selective detection of MP. The hollow structure possesses a specific surface area and porous matrix, which not only increases the exposure of active sites but also enhances the efficiency of mass and electron transport. Consequently, this structure significantly enhances the catalytic activity by reducing transport distances. The introduced MIPs provide the specific recognition sites for MP. And Ce (III) can excite aggregation induced emission of AuNCs and enhance the fluorescent signal. The absolute fluorescence quantum yield (FLQY) of CeO@PDA@AuNCs-MIPs (1.41 %) was 12.8-fold higher than that of the GSH-AuNCs (0.11 %). With the presence of MP, Ce (IV)/Ce (III) species serve as the active sites to polarize and hydrolyze phosphate bonds to generate p-nitrophenol (p-NP), which can quench the fluorescent signal through the inner-filter effect. The as-prepared CeO@PDA@AuNCs-MIPs nanozyme-based fluorescence method for MP detection displayed superior analytical performances with wide linearities range of 0.45-125 nM and the detection limit of 0.15 nM. Furthermore, the designed method offers satisfactory practical application ability. The developed method is simple and effective for the in-field detection.
对氧磷（MP）是一种剧毒、高效且广谱的有机磷农药，对生态环境和人类健康构成重大风险。许多检测MP的方法基于酶催化或抑制作用。但天然生物酶相对昂贵且易失活，使用寿命短。作为具有类酶特性的纳米技术独特工具，纳米酶受到越来越多的关注。然而，很大一部分纳米酶缺乏内在特异性，成为限制其在生化分析中应用的主要障碍。在此，我们采用一锅法反相微乳液聚合将金纳米簇（AuNCs）与分子印迹聚合物（MIPs）、聚多巴胺（PDA）和空心CeO纳米球相结合，合成具有高磷酸酶样活性的亮红橙色荧光探针（CeO@PDA@AuNCs-MIPs）用于选择性检测MP。空心结构具有比表面积和多孔基质，不仅增加了活性位点的暴露，还提高了质量和电子传输效率。因此，这种结构通过缩短传输距离显著增强了催化活性。引入的MIPs为MP提供了特异性识别位点。并且Ce（III）能激发AuNCs的聚集诱导发光并增强荧光信号。CeO@PDA@AuNCs-MIPs的绝对荧光量子产率（FLQY）（1.41%）比谷胱甘肽-AuNCs（0.11%）高12.8倍。在MP存在下，Ce（IV）/Ce（III）物种作为活性位点使磷酸酯键极化并水解生成对硝基苯酚（p-NP），其可通过内滤效应淬灭荧光信号。所制备的基于CeO@PDA@AuNCs-MIPs纳米酶的MP检测荧光方法具有优异的分析性能，线性范围宽达0.45 - 125 nM，检测限为0.15 nM。此外，所设计的方法具有令人满意的实际应用能力。所开发的方法用于现场检测简单有效。
