Unusual switchable peroxidase-mimicking nanozyme for the determination of proteolytic biomarker
Unusual switchable peroxidase-mimicking nanozyme for the determination of proteolytic biomarker
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DOI：
10.1007/s12274-018-2241-3
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发表时间：
2019-03-01
期刊：
影响因子：
9.9
通讯作者：
Cao, Cuong
中科院分区：
文献类型：
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作者：
McVey, Claire;Logan, Natasha;Cao, Cuong
检测源自生物流体或污染微生物的酶生物标志物在临床诊断和食品安全中至关重要。在此，我们提出了一种简单，低成本和易于使用的传感方法的基础上切换过氧化物酶模拟活性的等离子体金纳米粒子（AuNPs），可以催化氧化的3，3 '，5' 5-四甲基联苯胺（TMB）的蛋白酶的测定。金纳米粒子的表面改性与酪蛋白，显示出双重功能。涂层分子的第一个功能是抑制高达77.1%的固有的过氧化物酶模拟活性的金纳米粒子，由于表面屏蔽效应。其次，酪蛋白还充当酶生物标志物的识别位点。在蛋白酶的存在下，酶结合并催化AuNP表面上的涂层的降解，导致过氧化物酶模拟活性的恢复。这在蓝色产物（氧化的TMB）的显影中目视显示，或在370和650 nm处的吸光度增加的光谱中显示。该机制允许在90分钟内检测44 ng中心点mL（-1）的蛋白酶。该纳米传感器规避了与Curr（e）nt检测方法在易用性、与即时检测的兼容性、低成本生产和短分析时间方面相关的问题。该传感方法还被应用于检测超热处理（UHT）牛奶和合成人尿液样本中掺入的蛋白酶，检测限分别为490和176 ng中心点mL（-1），显示出巨大的潜力临床诊断、食品安全和质量控制。
Detection of enzyme biomarkers originating from either bio-fluids or contaminating microorganisms is of utmost importance in clinical diagnostics and food safety. Herein, we present a simple, low-cost and easy-to-use sensing approach based on the switchable peroxidase-mimicking activity of plasmonic gold nanoparticles (AuNPs) that can catalyse for the oxidation of 3,3',5'5-tetramethylbenzidine (TMB) for the determination of protease enzyme. The AuNP surface is modified with casein, showing dual functionalities. The first function of the coating molecule is to suppress the intrinsic peroxidase-mimicking activity of AuNPs by up to 77.1%, due to surface shielding effects. Secondly, casein also functions as recognition sites for the enzyme biomarker. In the presence of protease, the enzyme binds to and catalyses the degradation of the coating layer on the AuNP surface, resulting in the recovery of peroxidase-mimicking activity. This is shown visually in the development of a blue colored product (oxidised TMB) or spectroscopically as an increase in absorbance at 370 and 650 nm. This mechanism allows for the detection of protease at 44 ng center dot mL(-1) in 90 min. The nanosensor circumvents issues associated with curr(e)nt methods of detection in terms of ease of use, compatibility with point-of-care testing, low-cost production and short analysis time. The sensing approach has also been applied for the detection of protease spiked in ultra-heat treated (UHT) milk and synthetic human urine samples at a limit of detection of 490 and 176 ng center dot mL(-1), respectively, showing great potential in clinical diagnostics, food safety and quality control.