背景:独特的尺寸,物理和化学性质,纳米酶的超高稳定性在传感领域引起了广泛的关注,但是提高纳米酶的催化活性仍然是一个紧迫的问题。鉴于金属纳米粒子具有超高的模拟酶活性和多酶催化的优势,开发了整合双过氧化物酶样(POD)活性的Au修饰的MoS2纳米片(MoS2/AuNS)。
结果:通过优化和调整AuNP的密度,以及它的形态和其他参数,获得了MoS2纳米片上AuNPs的单分散和高密度分布,可以大大提高MoS2/AuNS的POD样活性。应用Nafion溶液辅助MoS2/AuNS在电极表面改性,以提高其稳定性。利用导电Nafion溶液在SPCE上修饰MoS2/AuNS纳米酶,构建了电化学H2O2检测平台。并且带负电荷的磺酸基团可以消除带负电荷的电活性物质以提高特异性。然后用抗坏血酸刺激肿瘤细胞产生H2O2作为治疗模型,建立了细胞裂解物中H2O2的超灵敏计时容量法检测方法。ΔQ的对数和H2O2浓度的对数在1μM和500mM之间显示出良好的线性关系,LOD值为0.3μM。
结论:开发的H2O2传感器具有出色的稳定性,重现性(RSD=2.3%,n=6)和选择性,实现了细胞裂解物中H2O2的定量检测。与用于细胞裂解物中H2O2的商业荧光检测试剂盒相比,值得一提的是,本研究开发的电化学H2O2传感器更简单、更快速,具有更高的灵敏度和更低的成本。这为基于H2O2的准确检测的疾病诊断和治疗评价提供了潜在的替代。
BACKGROUND: The unique size, physical and chemical properties, and ultra-high stability of nanozymes have attracted extensive attentions in sensing, but improvement of catalytic activity of the nanozymes is still an urgent issue. Given the ultra-high simulated enzyme activity of metal nanoparticles and the advantage of multi-enzyme catalysis, an Au-decorated MoS2 nanosheets (MoS2/Au NS) integrating the double peroxidase-like (POD) activity is developed.
RESULTS: By optimizing and adjusting the density of AuNPs, as well as its morphology and other parameters, a monodisperse and high-density distribution of AuNPs on MoS2 nanosheets was obtained, which can greatly improve the POD-like activity of MoS2/Au NS. Nafion solution was applied to assist the modification of MoS2/Au NS on the electrode surface so as to improved its stability. An electrochemical H2O2 detection platform was constructed by modifying MoS2/Au NS nanozyme on the SPCE using the conductive Nafion solution. And the negatively charged sulfonic acid group can eliminate negatively charged electroactive substances to improve the specificity. Then ascorbic acid was used to stimulate tumor cells to produce H2O2 as therapeutic model, an ultrasensitive chronocoulometry detection for H2O2 in cell lysate was established. The logarithmically of ΔQ and the logarithmically of H2O2 concentration showed a good linear relationship between 1 μM and 500 mM, with a LOD value of 0.3 μM.
CONCLUSIONS: The developed H2O2 sensor has excellent stability, reproducibility (RSD = 2.3 %, n = 6) and selectivity, realized the quantitative detection of H2O2 in cell lysate. Compared with commercial fluorescence detection kits for H2O2 in cell lysate, it is worth mentioning that the electrochemical H2O2 sensor developed in this study is simpler and faster, with higher sensitivity and lower cost. This provides a potential substitute for disease diagnosis and treatment evaluation based on accurate detection of H2O2.