Munteanu Irina Georgiana, Apetrei Constantin
Department of Chemistry, Physics and Environment, Faculty of Sciences and Environment, Dunărea de Jos University of Galaţi, 47 Domneasca Street, 800008 Galaţi, Romania.
Materials (Basel). 2022 Apr 29;15(9):3221. doi: 10.3390/ma15093221.
The purpose of our research was to develop a new enzymatic biosensor, GPH-MnPc-Tyr/SPE, using as a support screen-printed carbon electrode (SPE) modified with graphene, manganese phthalocyanine, and tyrosinase, with the aim of developing sensitive detection of chlorogenic acid (CGA). To immobilise tyrosinase on the sensor surface, crosslinking with the glutaraldehyde technique was used, thus increasing the enzyme bioactivity on this electrode. The modified electrode has a great catalytic effect on the electrochemical redox of chlorogenic acid, compared to the simple, unmodified SPE. The peak current response of the biosensor for CGA was linear in the range of 0.1-10.48 μM, obtaining a calibration curve using cyclic voltammetry (CV) and square-wave voltammetry (SWV). Subsequently, the detection limit (LOD) and the quantification limit (LOQ) were determined, obtaining low values, i.e., LOD = 1.40 × 10 M; LOQ = 4.69 × 10 M by cyclic voltammetry and LOD = 2.32 × 10 M; LOQ = 7.74 × 10 M, by square-wave voltammetry (SWV). These results demonstrate that the method is suitable for the detection of CGA in nutraceutical formulations. Therefore, GPH-MnPc-Tyr/SPE was used for the quantitative determination of CGA in three products, by means of cyclic voltammetry. The Folin-Ciocalteu spectrophotometric assay was used for the validation of the results, obtaining a good correlation between the voltammetric method and the spectrophotometric one, at a confidence level of 95%. Moreover, by means of the DPPH method, the antioxidant activity of the compound was determined, thus demonstrating the antioxidant effect of CGA in all nutraceuticals studied.
我们研究的目的是开发一种新型酶生物传感器GPH-MnPc-Tyr/SPE，它以用石墨烯、锰酞菁和酪氨酸酶修饰的丝网印刷碳电极（SPE）作为载体，旨在实现对绿原酸（CGA）的灵敏检测。为了将酪氨酸酶固定在传感器表面，采用了戊二醛技术进行交联，从而提高了该电极上的酶生物活性。与简单的未修饰SPE相比，修饰电极对绿原酸的电化学氧化还原具有很大的催化作用。该生物传感器对CGA的峰值电流响应在0.1-10.48 μM范围内呈线性，通过循环伏安法（CV）和方波伏安法（SWV）获得校准曲线。随后，测定了检测限（LOD）和定量限（LOQ），得到了较低的值，即通过循环伏安法LOD = 1.40×10⁻⁶ M；LOQ = 4.69×10⁻⁶ M，通过方波伏安法（SWV）LOD = 2.32×10⁻⁶ M；LOQ = 7.74×10⁻⁶ M。这些结果表明该方法适用于营养制剂中CGA的检测。因此，通过循环伏安法，GPH-MnPc-Tyr/SPE用于三种产品中CGA的定量测定。采用Folin-Ciocalteu分光光度法对结果进行验证，在95%的置信水平下，伏安法与分光光度法之间具有良好的相关性。此外，通过DPPH法测定了该化合物的抗氧化活性，从而证明了CGA在所有研究的营养制剂中的抗氧化作用。
