Highly sensitive colorimetric detection of 17 beta-estradiol using split DNA aptamers immobilized on unmodified gold nanoparticles

作者：Liu Jinchuan; Bai Wenhui; Niu Shucao; Zhu Chao; Yang Shuming; Chen Ailiang^*

来源：Scientific Reports, 2014, 4(1): 7571.

DOI：10.1038/srep07571

Gold nanoparticle (AuNP) based colorimetric aptasensor have been developed for many analytes recently largely because of the ease of detection, high sensitivity, and potential for high-throughput analysis. Most of the target aptamers for detection have short sequences. However, the approach shows poor performance in terms of detection sensitivity for most of the long-sequence aptamers. To address this problem, for the first time, we split the 76 mer aptamer of 17 beta-estradiol into two short pieces to improve the AuNP based colorimetric sensitivity. Our results showed that the split P1 + P2 still retained the original 76 mer aptamer's affinity and specificity but increased the detection limit by 10-fold, demonstrating that as low as 0.1 ng/mL 17 beta-estradiol could be detected. The increased sensitivity may be caused by lower aptamer adsorption concentration and a lower affinity to the AuNPs of a short single-strand DNA (ssDNA) sequence. Our study provided a new way to use long-sequence aptamers to develop a highly sensitive AuNP-based colorimetric aptasensor.

• 出版日期2014-12-19
• 单位中国农业科学院农业质量标准与检测技术研究所