Andrade César A S, Nascimento Jéssica M, Oliveira Idjane S, de Oliveira Carlos V J, de Melo Celso P, Franco Octávio L, Oliveira Maria D L
Programa de Pós-Graduação em Inovação Terapêutica, Universidade Federal de Pernambuco, 50670-901 Recife, PE, Brazil; Departamento de Bioquímica, Universidade Federal de Pernambuco, 50670-901 Recife, PE, Brazil.
Programa de Pós-Graduação em Inovação Terapêutica, Universidade Federal de Pernambuco, 50670-901 Recife, PE, Brazil.
Colloids Surf B Biointerfaces. 2015 Nov 1;135:833-839. doi: 10.1016/j.colsurfb.2015.03.037. Epub 2015 Mar 24.
Unusual methods for specific detection of pathogenic bacteria are becoming key points for control and identification of problems related to health and (bio)safety. In this context, this work aims to propose a new approach for the development of nanostructured biosensors based on carbon nanotubes (CNTs) and antimicrobial peptides for bacterial detection. Firstly, the antimicrobial peptide clavanin A (ClavA) was chemically immobilized on CNTs and surface-immobilized ClavA was used to detect Klebsiella pneumoniae, Enterococcus faecalis, Escherichia coli and Bacillus subtilis in a direct assay format. We used electrochemical impedance spectroscopy technique to evaluate the effectiveness and sensitivity of the ClavA-based biosensors by measuring the modifications in their electrochemical responses before and after incubation in presence of different bacteria concentrations. The biosensor was able to discriminate between bacteria concentrations in the 10(2)-10(6)CFU mL(-1) range. Atomic force microscopy analysis confirmed the biosensor functionality for bacterial recognition. This new sensor system was capable of differentiating between Gram-positive and Gram-negative bacteria, since ClavA showed different affinities toward the pathogenic bacteria species.
用于特定病原菌检测的非常规方法正成为控制和识别与健康及（生物）安全相关问题的关键所在。在此背景下，本研究旨在提出一种基于碳纳米管（CNT）和抗菌肽的新型纳米结构生物传感器用于细菌检测的开发方法。首先，将抗菌肽克拉瓦宁A（ClavA）化学固定在碳纳米管上，并采用表面固定的ClavA以直接检测法检测肺炎克雷伯菌、粪肠球菌、大肠杆菌和枯草芽孢杆菌。我们运用电化学阻抗谱技术，通过测量在不同细菌浓度下孵育前后其电化学响应的变化，来评估基于ClavA的生物传感器的有效性和灵敏度。该生物传感器能够区分10² - 10⁶ CFU mL⁻¹范围内的细菌浓度。原子力显微镜分析证实了该生物传感器用于细菌识别的功能。这种新型传感器系统能够区分革兰氏阳性菌和革兰氏阴性菌，因为ClavA对不同病原菌表现出不同的亲和力。
