School of Chemistry and Environment, Key Laboratory of Environmental Functional Materials of Yunnan Province Education Department, Yunnan Minzu University, Kunming, 650500, PR China.
College of Applied Technology, Yunnan Minzu University, Kunming, 650500, PR China.
Chemosphere. 2024 Sep;364:143171. doi: 10.1016/j.chemosphere.2024.143171. Epub 2024 Aug 27.
A fluorescent-colorimetric dual-signal platform, N, S co-doped carbon dots functionalized silver nanoparticles (NS-CDs-AgNPs), was designed in situ by reducing AgNO in the presence of N, S co-doped carbon dots (NS-CDs) under the assistance of microwave irradiation for glucose determination. With the formation of silver nanoparticles (AgNPs), the intrinsic fluorescence of NS-CDs was quenched, showing the fluorescence state was off. Whereas the fluorescence of NS-CDs can be switched on when a trace amount of HO was added. Based on this novel phenomenon, the peroxidase-like activity of NS-CDs-AgNPs by using 3,3',5,5'-tetramethylbenzidine (TMB) chromogen and HO as substrates was evaluated. The K values of the prepared probe for HO and TMB were 0.84 mM and 0.01 mM with the V of 6.65 × 10 M S and 3.01 × 10 M S, respectively. The results showed that NS-CDs-AgNPs had good peroxidase-like activity and strong affinity to TMB and HO. It confirmed that there is a redox interaction between AgNPs and HO, and HO can oxidize Ag to produce Ag, which is the main reason that the fluorescence of NS-CDs-AgNPs can be activated by HO. The hydroxyl radical (·OH) was formed in the process of reaction, which can further oxidize TMB for color reaction. Meanwhile, glucose can be oxidized to produce HO in the presence of glucose oxidase (GOx). Based on the phenomenon, a fluorimetric and colorimetric dual-mode sensor for glucose detection was established. Satisfactory results were obtained with the linear range of 0.1-80 μM for fluorimetric mode and 0.5-5 μM for colorimetric mode, respectively. Additionally, the LOD was below 0.32 μM and 0.21 μM, respectively. The method was successfully applied to determine the glucose in human serum with satisfactory recovery and RSD.
一种荧光比色双信号平台，N，S 共掺杂碳点功能化的银纳米粒子（NS-CDs-AgNPs），是通过在微波辐射的辅助下，在存在 N，S 共掺杂碳点（NS-CDs）的情况下还原 AgNO 原位设计的，用于葡萄糖测定。随着银纳米粒子（AgNPs）的形成，NS-CDs 的本征荧光被猝灭，呈现荧光状态关闭。而当加入痕量的 HO 时，NS-CDs 的荧光可以打开。基于这一新颖现象，通过使用 3,3',5,5'-四甲基联苯胺（TMB）显色剂和 HO 作为底物，评估了 NS-CDs-AgNPs 的过氧化物酶样活性。制备探针对 HO 和 TMB 的 K 值分别为 0.84 mM 和 0.01 mM，V 值分别为 6.65×10 M S 和 3.01×10 M S。结果表明，NS-CDs-AgNPs 具有良好的过氧化物酶样活性和对 TMB 和 HO 的强亲和力。证实了 AgNPs 和 HO 之间存在氧化还原相互作用，HO 可以将 Ag 氧化产生 Ag，这是 NS-CDs-AgNPs 的荧光可以被 HO 激活的主要原因。反应过程中形成了羟基自由基（·OH），它可以进一步氧化 TMB 进行显色反应。同时，葡萄糖在葡萄糖氧化酶（GOx）存在下可以氧化产生 HO。基于这一现象，建立了一种用于葡萄糖检测的荧光和比色双模式传感器。荧光模式的线性范围为 0.1-80 μM，比色模式的线性范围为 0.5-5 μM，均获得了令人满意的结果。此外，LOD 分别低于 0.32 μM 和 0.21 μM。该方法成功应用于人血清中葡萄糖的测定，回收率和 RSD 均令人满意。
