Plasmonic colorimetric biosensor for visual detection of telomerase activity based on horseradish peroxidase-encapsulated liposomes and etching of Au nanobipyramids

• Published in: Sensors and actuators. B, Chemical Vol. 296; p. 126646
• Main Authors: Wang, Danni, Zhang, Yingzhi, Zhao, Xiayu, Xu, Zhangrun
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.10.2019
• Subjects: Au nanobipyramids; Liposome-based amplification; Multicolor visual detection; Plasmonic colorimetry; Telomerase; Au nanobipyramids; Liposome-based amplification; Telomerase; Plasmonic colorimetry; Multicolor visual detection
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2019.126646

[Display omitted] •A sensitive plasmonic colorimetric sensor was constructed for detecting telomerase.•Au NBPs as plasmonic substrate for telomerase assay led to multiply vivid colors.•Liposomes were employed to encapsulate HRP for cascaded signal amplification.•The LODs were 1 HeLa cell for LSPR measure and 20 HeLa cells for visual inspection. Telomerase aberrant activation is a critical feature in the vast majority of cancers. To visualize telomerase expression level in tumor cells, we developed a plasmonic colorimetric sensor for highly sensitive detection of telomerase activity by integrating an excellent etching substrate Au nanobipyramids (Au NBPs) with a liposome-based signal amplification strategy. Upon telomerase-triggered extension, the telomerase activity was converted into the amount of the attached horseradish peroxidase-encapsulated liposomes (HRP-Ls) on the surfaces of magnetic beads. Afterwards, HRP was liberated from the liposomes following the addition of H2O2-3,3′,5,5′-tetramethylbenzidine sulfate (TMB) substrate, and then the oxidation reaction between H2O2 and TMB was initiated to form TMB2+. The morphological evolution of Au NBPs relied on the TMB2+-mediated etching reaction, which gave rise to tremendous localized surface plasmon resonance (LSPR) responses and concomitant tonality transitions. Benefiting from cascaded signal amplification capacity of HRP-Ls and the intriguing optical properties of Au NBPs, an impressive sensitivity toward telomerase was obtained with detection limits equivalent to 1 HeLa cell for LSPR peak measurement and a visual detection limit of 20 HeLa cells. Furthermore, a facile and portable kit was fabricated for visual evaluation of telomerase activity in different cell lines.