Xu Huiren, Wang Li, Luo Jinping, Song Yilin, Liu Juntao, Zhang Song, Cai Xinxia
State Key Laboratory of Transducer Technology, Institute of Electronics Chinese Academy of Sciences, Beijing 100190, China.
Sensors (Basel). 2015 Jan 8;15(1):1008-21. doi: 10.3390/s150101008.
It is difficult to determine dopamine (DA) and 5-hydroxytryptamine (5-HT) accurately because of the interference of ascorbic acid (AA) in vitro, which has a high concentration and can be oxidized at a potential close to DA and 5-HT at a conventional electrode, combined with the overlapping voltammetric signal of DA and 5-HT at a bare electrode. Herein, chitosan (CS) was used as a stabilizing matrix by electrochemical reaction, and multi-walled carbon nanotubes (MWCNTs) were modified onto the microelectrode array (MEA). The CS-MWCNT hybrid film-modified MEA was quite effective at simultaneously recognizing these species in a mixture and resolved the overlapping anodic peaks of AA, DA and 5-HT into three well-defined oxidation peaks in differential pulse voltammetry (DPV) at -80 mV, 105 mV and 300 mV (versus Ag|AgCl), respectively. The linear responses were obtained in the range of 5 × 10(-6) M to 2 × 10(-4) M for DA (r = 0.996) and in the range of 1 × 10(-5) M to 3 × 10(-4) M for 5-HT (r = 0.999) using the DPV under the presence of a single substance. While DA coexisted with 5-HT in the interference of 3 × 10(-4) M AA, the linear responses were obtained in the range of 1 × 10(-5) M to 3 × 10(-4) M for selective molecular recognition of DA (r = 0.997) and 5-HT (r = 0.997) using the DPV. Therefore, this proposed MEA was successfully used for selective molecular recognition and determination of DA and 5-HT using the DPV, which has a potential application for real-time determination in vitro experiments.
由于体外抗坏血酸（AA）的干扰，准确测定多巴胺（DA）和5-羟色胺（5-HT）很困难。AA浓度高，在传统电极上可在接近DA和5-HT的电位下被氧化，且在裸电极上DA和5-HT的伏安信号重叠。在此，壳聚糖（CS）通过电化学反应用作稳定基质，多壁碳纳米管（MWCNT）被修饰到微电极阵列（MEA）上。CS-MWCNT混合膜修饰的MEA在同时识别混合物中的这些物质方面非常有效，并且在差分脉冲伏安法（DPV）中，在-80 mV、105 mV和300 mV（相对于Ag|AgCl）处将AA、DA和5-HT的重叠阳极峰解析为三个清晰定义的氧化峰。在单一物质存在下，使用DPV时，DA的线性响应范围为5×10⁻⁶ M至2×10⁻⁴ M（r = 0.996），5-HT的线性响应范围为1×10⁻⁵ M至3×10⁻⁴ M（r = 0.999）。当DA与5-HT在3×10⁻⁴ M AA的干扰中共存时，使用DPV对DA（r = 0.997）和5-HT（r = 0.997）进行选择性分子识别的线性响应范围为1×10⁻⁵ M至3×10⁻⁴ M。因此，所提出的MEA成功用于使用DPV对DA和5-HT进行选择性分子识别和测定，这在体外实验的实时测定中具有潜在应用。
