Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Syiah Kuala, Darussalam, Banda Aceh 23111, Indonesia.
Department of Chemical Sciences, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi 43600, Selangor Darul Ehsan, Malaysia.
Biosensors (Basel). 2022 Aug 17;12(8):650. doi: 10.3390/bios12080650.
A new electrochemical DNA biosensor based on mercaptopropionic acid (MPA)-capped ZnS quantum dots (MPA-ZnS QDs) immobilization matrix for covalent binding with 20-base aminated oligonucleotide has been successfully developed. Prior to the modification, screen-printed carbon paste electrode (SPE) was self-assembled with multilayer gold nanoparticles (AuNPs) and cysteamine (Cys). The inclusion of MPA-ZnS QDs semiconducting material in modified electrodes has enhanced the electron transfer between the SPE transducer and DNA leading to improved bioanalytical assay of target biomolecules. Electrochemical studies performed by cyclic voltammetry (CV) and differential pulsed voltammetry (DPV) demonstrated that the MPA-ZnS QDs modified AuNPs electrode was able to produce a lower charge transfer resistance response and hence higher electrical current response. Under optimal conditions, the immobilized synthetic DNA probe exhibited high selectivity towards synthetic target DNA. Based on the DPV response of the reduction of anthraquinone monosulphonic acid (AQMS) redox probe, the MPA-ZnS QDs-based electrochemical DNA biosensor responded to target DNA concentration from 1 × 10 μM to 1 × 10 μM with a sensitivity 1.2884 ± 0.12 µA, linear correlation coefficient (R) of 0.9848 and limit of detection (LOD) of 1 × 10 μM target DNA. The DNA biosensor exhibited satisfactory reproducibility with an average relative standard deviation (RSD) of 7.4%. The proposed electrochemical transducer substrate has been employed to immobilize the aminated Arowana fish () DNA probe. The DNA biosensor showed linearity to target DNA from 1 × 10 to 1 × 10 µM (R = 0.9785) with sensitivity 1.1251 ± 0.243 µA and LOD of 1 × 10 µM. The biosensor has been successfully used to determine the gender of Arowana fish without incorporating toxic raw materials previously employed in the hazardous processing conditions of polypyrrole chemical conducting polymer, whereby the cleaning step becomes difficult with thicker films due to high levels of toxic residues from the decrease in polymerization efficacy as films grew.
一种基于巯基丙酸（MPA）封端的 ZnS 量子点（MPA-ZnS QDs）固定基质的新型电化学 DNA 生物传感器，用于与 20 个碱基的氨化寡核苷酸共价结合，已成功开发。在修饰之前，丝网印刷碳糊电极（SPE）通过多层金纳米粒子（AuNPs）和半胱氨酸（Cys）自组装。修饰电极中包含 MPA-ZnS QDs 半导体材料，增强了 SPE 换能器与 DNA 之间的电子转移，从而改善了目标生物分子的生物分析测定。通过循环伏安法（CV）和差分脉冲伏安法（DPV）进行的电化学研究表明，MPA-ZnS QDs 修饰的 AuNPs 电极能够产生较低的电荷转移电阻响应，从而产生更高的电流响应。在最佳条件下，固定化合成 DNA 探针对合成靶 DNA 表现出高选择性。基于蒽醌一磺酸（AQMS）氧化还原探针还原的 DPV 响应，基于 MPA-ZnS QDs 的电化学 DNA 生物传感器对靶 DNA 浓度从 1×10μM 到 1×10μM 做出响应，灵敏度为 1.2884±0.12μA，线性相关系数（R）为 0.9848，检测限（LOD）为 1×10μM 靶 DNA。该 DNA 生物传感器具有令人满意的重现性，平均相对标准偏差（RSD）为 7.4%。所提出的电化学换能器基质已用于固定氨化龙鱼（）DNA 探针。DNA 生物传感器对靶 DNA 从 1×10 到 1×10μM 表现出线性关系（R=0.9785），灵敏度为 1.1251±0.243μA，检测限为 1×10μM。该生物传感器已成功用于确定龙鱼的性别，而无需使用以前在聚吡咯化学导电聚合物危险处理条件中使用的有毒原料，由于聚合效率降低导致毒性残留物水平升高，因此较厚的薄膜会使清洗步骤变得困难。
