Sun Panpan, Chen Juan, Li Qian, Luo Mingyue, Chang Wenzhuo, Xue Zhonghua
Key Laboratory of Water Security and Water Environment Protection in Plateau Intersection (NWNU), Ministry of Education, Key Lab of Bioelectrochemistry and Environmental Analysis of Gansu Province, College of Chemistry and Chemical Engineering, Northwest Normal University, 730070, Lanzhou, Gansu, China.
Key Laboratory of Water Security and Water Environment Protection in Plateau Intersection (NWNU), Ministry of Education, Key Lab of Bioelectrochemistry and Environmental Analysis of Gansu Province, College of Chemistry and Chemical Engineering, Northwest Normal University, 730070, Lanzhou, Gansu, China.
Anal Chim Acta. 2025 Feb 8;1338:343596. doi: 10.1016/j.aca.2024.343596. Epub 2024 Dec 30.
Reliable and selective detection of dopamine is crucial for the early diagnosis of various diseases. Transition metal based-nanozymes have shown great promise in the field of colorimetric detection of dopamine due to their remarkable stability and exceptional catalytic efficiency. However, these transition metal-based nanozymes typically function through a chromogenic reaction that relies on additional organic substrates, such as 3,3',5,5'-tetramethylbenzidine, to generate a detectable signal. The presence of various co-existing substances can cause serious disturbances due to their possibly similar oxidation potentials.
In this study, we proposed a 3,3',5,5'-tetramethylbenzidine-free strategy based on the self-signal of dopamine to achieve reliable and selective detection. CoFeO nanozymes with catalase-like activity was selected as a catalyst to accelerate the polymerization of dopamine to reduce the reaction time and harsh conditions required for its self-polymerization. As neither ascorbic acid nor uric acid can be oxidized into colored products, the 3,3',5,5'-tetramethylbenzidine-free sensor provides superior selectivity and effectiveness compared with the most 3,3',5,5'-tetramethylbenzidine-used sensor. The proposed strategy enabled quantitative detection of dopamine within a range of 5-80 μM, with a detection limit of 0.233 μM (R = 0.998). The limit of quantitation was 10.6 μM, and the method demonstrated a precision of 2.04 %. The recovery percentage for dopamine ranges from 97.0 % to 106 %.
The proposed 3,3',5,5'-tetramethylbenzidine-free strategy offers a versatile approach for dopamine monitoring with high specificity and stability in bioanalytical applications. In addition, the strategy proposed by us also offers a rational framework for designing and fabricating highly selective sensors, thereby broadening the application of the nanozymes with catalase-like activity in bioanalysis.
可靠且选择性地检测多巴胺对于多种疾病的早期诊断至关重要。基于过渡金属的纳米酶因其卓越的稳定性和非凡的催化效率，在多巴胺比色检测领域展现出巨大潜力。然而，这些基于过渡金属的纳米酶通常通过依赖额外有机底物（如3,3',5,5'-四甲基联苯胺）的显色反应来产生可检测信号。各种共存物质的存在可能因其相似的氧化电位而导致严重干扰。
在本研究中，我们提出了一种基于多巴胺自身信号的无3,3',5,5'-四甲基联苯胺策略，以实现可靠且选择性的检测。选择具有过氧化氢酶样活性的CoFeO纳米酶作为催化剂，加速多巴胺的聚合反应，从而缩短其自聚合所需的反应时间和苛刻条件。由于抗坏血酸和尿酸都不能被氧化成有色产物，与大多数使用3,3',5,5'-四甲基联苯胺的传感器相比，这种无3,3',5,5'-四甲基联苯胺的传感器具有更高的选择性和有效性。所提出的策略能够在5 - 80 μM范围内对多巴胺进行定量检测，检测限为0.233 μM（R = 0.998）。定量限为10.6 μM，该方法的精密度为2.04%。多巴胺的回收率在97.0%至106%之间。
所提出的无3,3',5,5'-四甲基联苯胺策略为生物分析应用中高特异性和稳定性的多巴胺监测提供了一种通用方法。此外，我们提出的策略还为设计和制造高选择性传感器提供了合理框架，从而拓宽了具有过氧化氢酶样活性的纳米酶在生物分析中的应用。
