Carbon dots-inspired fluorescent cyclodextrins: competitive supramolecular "off–on" (bio)sensors. Issue 16 (16th April 2020)

• Record Type: Journal Article
• Authors: De los Reyes-Berbel, Eduardo; Ortiz-Gomez, Inmaculada; Ortega-Muñoz, Mariano; Salinas-Castillo, Alfonso; Capitan-Vallvey, Luis Fermin; Hernandez-Mateo, Fernando; Lopez-Jaramillo, Francisco Javier; Santoyo-Gonzalez, Francisco
• Is Part Of: Nanoscale. Volume 12:Issue 16(2020)
• Page Start: 9178
• Page End: 9185
• Publication Date: 2020-04-16
• Subjects: Nanoscience -- Periodicals; Nanotechnology -- Periodicals; 620.505
• DOI: 10.1039/d0nr01004a
• Languages: English
• ISSNs: 2040-3364

Abstract

Abstract : Fluorescent cyclodextrins (CDs) engineered by grafting the molecular fluorophore IPCA behave as carbon nanodot-appended CD "off–on" sensors of (bio)analytes and for analyzing glycosidase activity. Abstract : Chromophore-appended cyclodextrins combine the supramolecular loading capabilities of cyclodextrins (CDs) with the optical properties of the affixed chromophores. Among fluorescent materials, carbon dots (CNDs) are attractive and the feasibility of CND-appended CDs as sensors has been demonstrated by different authors. However, CNDs are intrinsically heterogeneous materials and their ulterior functionalization yields hybrid composites that are not well defined in terms of structure and composition. Inspired by the fluorescence properties of 5-oxo-1, 2, 3, 5-tetrahydroimidazo[1, 2- a ]pyridine-7-carboxylic acid (IPCA), the most paradigmatic of the molecular fluorophores detected in CNDs, herein we report two highly efficient synthetic chemical strategies for the preparation of IPCA-appended CDs that behave as CND-based CD "turn off–on" biosensors suitable for the analysis of cholesterol and β-galactosidase activity. We have deconstructed the CND–CD systems to demonstrate that (i) the role of CNDs is limited to acting as a support for the molecular fluorophores produced during their synthesis and (ii) the molecular fluorophores suffice for the determination of the enzymatic activity based on the quenching by p -nitrophenol as a sacrificial quencher.