Analytical Chemistry Department, Institute of Chemistry, São Paulo State University (UNESP), Araraquara 14800-060, São Paulo State, Brazil; Bioenergy Research Institute, São Paulo State University (UNESP), Araraquara 14800-060, São Paulo State, Brazil.
Analytical Chemistry Department, Institute of Chemistry, São Paulo State University (UNESP), Araraquara 14800-060, São Paulo State, Brazil; Bioenergy Research Institute, São Paulo State University (UNESP), Araraquara 14800-060, São Paulo State, Brazil.
J Chromatogr B Analyt Technol Biomed Life Sci. 2021 Jun 1;1174:122733. doi: 10.1016/j.jchromb.2021.122733. Epub 2021 Apr 29.
This work reports the development of a fast and reliable amperometric sensor for the detection of amino acids. The detector was constructed using copper nanoparticles (CuNPs) supported on reduced graphene oxide (RGO) modified glassy carbon electrode (CuNPs-RGO/GCE) and based on the application of high performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD). Under optimized isocratic HPAEC-PAD conditions (using 40 mmol L NaOH as mobile phase, flow rate of 0.30 mL min and detection potential of 0.45 V vs. Pd/PdO), the linear dynamic ranges of the concentration of amino acids obtained were 0.50-50 µmol L for lysine, 1.0-100 µmol L for alanine, glycine and serine, and 5.0-100 µmol L for leucine. The limits of detection (S/N = 3) obtained ranged from 0.10 (for lysine and leucine) to 0.50 µmol L (for alanine, glycine and serine) and sensitivity varied from 6.1 (for leucine) to 21.5 nA µmol L (for serine). The average recovery percentages ranged from 97% (for glycine) to 102% (for leucine and serine). The results obtained showed that the CuNPs-RGO/GCE has good long-term stability, repeatability and reproducibility; this makes the device suitable for application as an electrochemical detector. The successful application of the proposed method for the analysis of sugarcane vinasse demonstrates its suitability for separation and determination of amino acids in complex matrices.
本工作报道了一种用于检测氨基酸的快速可靠的安培传感器的开发。该检测器是使用负载在还原氧化石墨烯（RGO）上的铜纳米粒子（CuNPs）构建的，基于高效阴离子交换色谱与脉冲安培检测（HPAEC-PAD）的应用。在优化的等度 HPAEC-PAD 条件下（使用 40 mmol L NaOH 作为流动相，流速为 0.30 mL min 和检测电位为 0.45 V 相对于 Pd/PdO），获得的氨基酸浓度的线性动态范围为 0.50-50 μmol L 用于赖氨酸，1.0-100 μmol L 用于丙氨酸、甘氨酸和丝氨酸，5.0-100 μmol L 用于亮氨酸。获得的检测限（S/N = 3）范围从 0.10（用于赖氨酸和亮氨酸）到 0.50 μmol L（用于丙氨酸、甘氨酸和丝氨酸），灵敏度从 6.1（用于亮氨酸）到 21.5 nA μmol L（用于丝氨酸）。平均回收率范围从 97%（用于甘氨酸）到 102%（用于亮氨酸和丝氨酸）。结果表明，CuNPs-RGO/GCE 具有良好的长期稳定性、重复性和重现性；这使得该装置适合用作电化学检测器。所提出的方法成功应用于甘蔗废醪液的分析，证明其适合于复杂基质中氨基酸的分离和测定。
