基于碳纳米管修饰电极的胆碱电化学发光生物传感器研制

在碳纳米管(CNTs)和K3Fe(CN)6修饰的铂电极上吸附固定胆碱氧化酶,以鲁米诺为发光试剂,研制了胆碱电化学发光(ECL)生物传感器.CNTs可有效提高电极表面的电荷传输能力、提高电极表面的生物相容性和对酶分子的固载能力;K3Fe(CN)6对酶活性具有激活作用,同时对H2O2增敏的鲁米诺ECL有增强作用,均有利于提...

Development of Electrochemiluminescent Biosensor for Choline Based on Carbon Nanotube Modified Platinum Electrode

An electrochemiluminescent (ECL) choline biosensor was developed by the drop coating of choline oxidase (ChOx) onto a carbon nanotubes (CNTs)/potassium ferricyanide (K₃Fe(CN)₆)-modified platinum electrode with ECL of luminol as readout signal. CNTs improved the loading capacity of enzyme, as well as the biocompatibility and electron transfer of the electrode surface, whereas K₃Fe(CN)₆ facilitated activation of the enzyme and enhancement of the ECL signal, so the developed biosensor exhibited excellent analytical performance. The biosensor gave optimal results while the Pt electrode was modified with 4 μL of 0.33 g L⁻¹ CNTs dispersoid, 2 μL of 0.1 M K₃Fe(CN)₆ and 1.5U of ChOx. In the PBS buffer (pH 7.4) containing 8 × 10⁻⁶ M luminol, the ECL signal linearly responded to the concentration of choline from 1 × 10⁻⁷ M to 4 × 10⁻³ M (r = 0.994) with a detection limit of 1.21 × 10⁻⁸ M under 30 (C. The developed biosensor was applied to measure the concentration of choline in rat blood sample and the result was satisfied, with an average recovery of 101.1%. The as-prepared biosensor showed good stability and repeatability.