Synthesis of Functionalized Silica Particles for Label‐free Detection of PTP1B Using FRET

• Published in: Bulletin of the Korean Chemical Society Vol. 40; no. 12; pp. 1172 - 1177
• Main Authors: Durgannavar, Trishaladevi, Ahn, Dohee, Hwang, Ji Young, Yoon, Sun‐Young, Kang, Hyo Jin, Chung, Sang J.
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley‐VCH Verlag GmbH & Co. KGaA 01.12.2019; 대한화학회
• Subjects: Cell permeability; FRET; Label‐free; PTP1B; Silica nanoparticle; 화학
• ISSN: 1229-5949; 0253-2964; 1229-5949
• DOI: 10.1002/bkcs.11888

Silica nanoparticles (SiNPs, 30 and 70 nm) and microparticles (SiMPs, 10 μm) were functionalized with a PTP1B specific probe for label‐free fluorescence detection of PTP1B. Intrinsic tryptophan residues of PTP1B serve as the Förster resonance energy transfer (FRET) donor and the functionalized silica particles as the FRET acceptor. When a mixture of the functionalized SiNP and PTP1B is excited at tryptophan excitation maximum (280 nm), significant sensitized fluorescence was detected at 450 nm as a result of FRET. The limit of detection of PTP1B was found to be 29 and 70 nM for the functionalized 30 and 70 nm SiNP, respectively. Using this approach, PTP1B could be detected in E. coli cell lysate in which PTP1B was induced. The functionalized SiNP probe (SiNP/NA) was selective toward PTP1B over BSA, and the nanoparticles are able to penetrate into cells. Furthermore, the binding of PTP1B to the SiMPs could be visualized under a deep UV‐microscope. Silica nanoparticles (SiNPs) functionalized with a PTP1B‐specific probe equipped with 1‐naphthylamine (FRET acceptor) allow a label‐free fluorescence detection of PTP1B. Trp residues (FRET donors) in PTP1B (PDBID: 1LQF) are colored red.