School of Chemistry, Damghan University, Damghan 36716-41167, Iran.
School of Biology, Damghan University, Damghan 36716-41167, Iran.
Biosensors (Basel). 2022 Oct 28;12(11):939. doi: 10.3390/bios12110939.
The interaction of tyrosinase with sulfonated starch--polyaniline@graphene (SSt--PANI@G) nanocomposite was investigated by electrochemical methods. The activity of the immobilized tyrosinase (Tyase) was proved by the electrochemical detection of three substrates (L-dopa, caffeic acid, and catechol). The SSt--PANI@G nanocomposite was characterized by Fourier-transform infrared spectra (FT-IR), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray analysis (EDX), and thermogravimetric analysis (TGA). To immobilize tyrosinase on the surface of the nanocomposite, a simple drop-casting technique was used. The presence of sulfuric acid and hydroxyl groups in SSt, amine groups in PANI, and high surface-to-volume ratio and electrical conductivity of graphene in the prepared nanocomposite led to good enzyme immobilization on the electrode surface. The modified electrode showed a suitable catalytic effect on the electrochemical redox agent, compared with the bare electrode. The peak current responses for three substrates were studied with a calibration curve derived using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). In addition, the fabricated SSt-g-PANI@G/Tyase/GCE showed a more suitable response to catechol, L-dopa, and caffeic acid substrates, respectively.
通过电化学方法研究了酪氨酸酶与磺化淀粉-聚苯胺@石墨烯（SSt-PANI@G）纳米复合材料的相互作用。通过电化学检测三种底物（L-多巴、咖啡酸和儿茶酚）证明了固定化酪氨酸酶（Tyase）的活性。SSt-PANI@G 纳米复合材料通过傅里叶变换红外光谱（FT-IR）、X 射线衍射（XRD）、场发射扫描电子显微镜（FESEM）、能谱分析（EDX）和热重分析（TGA）进行了表征。为了将酪氨酸酶固定在纳米复合材料的表面上，采用了简单的滴铸技术。SSt 中的硫酸和羟基、PANI 中的胺基以及石墨烯的高表面积与体积比和导电性导致了酶在电极表面的良好固定化。与裸电极相比，修饰后的电极对电化学氧化还原试剂表现出合适的催化作用。通过循环伏安法（CV）和差分脉冲伏安法（DPV）得到校准曲线，研究了三种底物的峰电流响应。此外，制备的 SSt-g-PANI@G/Tyase/GCE 对儿茶酚、L-多巴和咖啡酸底物分别表现出更合适的响应。
