Electropolymerized poly(Toluidine Blue)-modified carbon felt for highly sensitive amperometric determination of NADH in flow injection analysis

Poly（pheniothiazine） films were prepared on a porous carbon felt（CF） electrode surface by an electrooxidative polymerization of three phenothiazine derivatives（i.e.,Tthionine（TN）,Toluidine Blue（TB） and Methylene Blue（MB）） from 0.1 mol/L phosphate buffer solution（pH 7.0）.Among the three phenothiazies,the poly（TB） film-modified CF exhibited an excellent electrocatalytic activity for the oxidation of nicotinamide adenine dinucleotide reduced form（NADH） at ＋0.2 V vs.Ag/AgCl.The poly（TB） film-modified CF was successfully used as working electrode unit of highly sensitive amperometric flow-through detector for NADH.The peak currents（peak heights） were almost unchanged,irrespective of a carrier flow rate ranging from 2.0 to 4.1 mL/min,resulting in the measurement of NADH（ca.30 samples/hr） at 4.1 mL/min.The peak current responses of NADH showed linear relationship over the concentration range from 1 to 30 μmol/L（sensitivity：0.318 μA/（μmol/L）;correlation coefficient：0.997）.The lower detection limit was found to be 0.3 μmol/L（S/N = 3）.

Study on electrode process of myoglobin at a polymerized Toluidine Blue film electrode

This paper reports the use of an electrochemically polymerized Toluidine Blue (TB) film electrode.The film on platinum electrode surface was analyzed with ESCA.The heterogeneous electron transfer processes of myoglobin at the polymerized TB film electrode have been investigated using in situ UV-visible spectroelectrochemistry.The formal potential(E°′)and electron transfer number(n)of myoglobin were calculated as E°′=0.045 V(vs.NHE)and n=0.99.The exhaustive reduction and oxidation electrolyses are achieved in 130 s and 110 s respectively,during a potential step between-0.4 V and+0.4 V.A formal heterogeneous electron transfer rate constant(ksh)of 1.09× 10^(-4) cm/s and a transfer coefficient(α)of 0.47 were obtained by cyclic voltabsorptometry,which indicated that myoglobin underwent a quasi-reversible electrode process at the polymerized TB film electrode.

抗坏血酸在聚甲苯胺蓝膜修饰的玻碳电极上的电催化氧化及流动注射分析

在玻碳电极上用循环伏安法电聚合一层聚甲苯胺蓝膜,该膜修饰电极对抗坏血酸(VC)的氧化具有良好的电催化作用,能够降低其过电位约100mV。将该修饰电极应用于流动注射能大大提高VC的检测灵敏度,其线性范围为2.0×10-7～1.2×10-3mol·L-1,检出限为4.8×10-8mol·L-1,连续注射检测,其电流信号能够保持稳定24h。

尿酸在甲苯胺蓝修饰电极上的循环伏安测定

目的:建立一种聚甲苯胺蓝修饰电极测定尿酸的新方法,为人体内尿酸含量的测定提出一条新的思路。方法:利用甲苯胺蓝在玻碳电极表面制备聚合物膜,用循环伏安法研究了尿酸(UA)在该电极上的电化学行为,并将电极用于实际尿样的测定。结果:在0.1 mol·L^(-1)(pH 7.0)的磷酸盐缓冲液中,UA 在聚甲苯胺蓝修饰电极上于0.373 V 处产生一灵敏的氧化峰,线性扫描伏安法测定其氧化峰电流与 UA 浓度在8×10^(-6)～3.0×10^(14)mol·L^(-1)范围内呈良好的线性关系(r=0.9971),检出限为5.0×10^(-6)mol·L^(-1)。结论:该电极制作简单,重现性好,可以用于实际尿样的测定,结果令人满意。

基于多壁碳纳米管修饰的葡萄糖生物传感器

用循环伏安法在玻碳电极表面电沉积了一层稳定的甲苯胺蓝聚合物膜，以此作为电子传递介体，结合多壁碳纳米管、壳聚糖（CHIT）、葡萄糖氧化酶（GOD）混合包埋制备出一种新型葡萄糖生物传感器，实验结果显示，用此法制备的传感器对葡萄特的线性响应范周为5．0×10^-6～2．0×10^-2mol／L，线性相关系数为0．9969。检测限为1×10^-6，响应时间为3．2S，并具有抗尿酸、抗坏血酸等干扰的特点。

用聚甲苯胺蓝修饰的玻碳电极同时测定多巴胺和抗坏血酸

研究了聚甲苯胺蓝修饰的玻碳电极的制备及其对多巴胺和抗坏血酸的电催化作用。由于多巴胺和抗坏血酸在该修饰电极的氧化还原电位相差约0.190 V(vs SCE),在同一溶液中,两者无需分离可以分别检出而互不干扰。其可检测的线性范围分别为4～1.8 mmol/L和2.0～3.2 mmol/L,检测下限分别为1.4μmol/L和0.8μmol/L。