Detection of native amino acids and peptides utilizing sinusoidal voltammetry.
Detection of native amino acids and peptides utilizing sinusoidal voltammetry.
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DOI：
10.1021/ac000543r
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发表时间：
2000-10
影响因子：
7.4
通讯作者：
S. Brazill;P. Singhal;W. Kuhr
中科院分区：
文献类型：
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作者：
S. Brazill;P. Singhal;W. Kuhr
使用正弦伏安法 (SV) 在铜微电极上检测天然氨基酸和肽。传统上，这些分子只能在用荧光或电活性标签衍生化后进行测量。在这项工作中，铜的电催化氧化反应用于检测未衍生化的肽和氨基酸。氧化反应在某种程度上独立于肽结构（即，它不限于芳香族氨基酸的检测），因此能够对所有测试的氨基酸和肽产生纳摩尔检测限。扫描技术，正弦伏安法，用于提供恒电位技术的灵敏度，而且还提供通过利用频域获得的选择性。由于每个分子的氧化而产生的频谱具有独特的“指纹”响应，该响应是由电极表面的氧化动力学产生的。通过检查频谱，即使是结构相似的分子也可以轻松区分。流动注射分析用于证明多种氨基酸和肽的灵敏和选择性检测。该技术还可以轻松地与分离步骤（即高效液相色谱或毛细管电泳）结合使用，而不会因吸附分析物而导致电极结垢。
Native amino acids and peptides were detected at a copper microelectrode using sinusoidal voltammetry (SV). Traditionally, these molecules can only be measured after derivatization with either a fluorescent or electroactive tag. In this work, an electrocatalytic oxidation reaction at copper is used to detect underivatized peptides and amino acids. The oxidation reaction is somewhat independent of peptide structure (i.e., it is not limited to the detection of aromatic amino acids) and is therefore able to produce nanomolar detection limits for all amino acids and peptides tested. A scanning technique, sinusoidal voltammetry, is used to provide the sensitivity of constant-potential techniques but also provide selectivity gained through utilization of the frequency domain. The frequency spectrum due to the oxidation of each molecule has a unique "fingerprint" response resulting from the kinetics of oxidation at the electrode surface. Through examination of the frequency spectra, even structurally similar molecules can be easily distinguished from one another. Flow injection analysis is used to demonstrate the sensitive and selective detection of a variety of amino acids and peptides. This technique can also be easily coupled to a separation step, i.e., high-performance liquid chromatography or capillary electrophoresis without electrode fouling from the adsorption of the analytes.