Bruni, Francesco Pedrini, Jacopo Bossio, Caterina Santiago-Gonzalez, Beatriz Meinardi, Francesco Bae, Wan Ki Klimov, Victor I. Lanzani, Guglielmo Brovelli, Sergio 2024-01-20T02:01:20Z 2024-01-20T02:01:20Z 2021-09-01 2017-03-24 1616-301X https://pubs.kist.re.kr/handle/201004/122940 Intracellular pH is a key parameter in many biological mechanisms and cell metabolism and is used to detect and monitor cancer formation and brain or heart diseases. pH-sensing is typically performed by fluorescence microscopy using pH-responsive dyes. Accuracy is limited by the need for quantifying the absolute emission intensity in living biological samples. An alternative with a higher sensitivity and precision uses probes with a ratiometric response arising from the different pH-sensitivity of two emission channels of a single emitter. Current ratiometric probes are complex constructs suffering from instability and cross-readout due to their broad emission spectra. Here, we overcome such limitations using a single-particle ratiometric pH probe based on dot-in-bulk CdSe/CdS nanocrystals (NCs). These nanostructures feature two fully-separated narrow emissions with different pH sensitivity arising from radiative recombination of core-and shell-localized excitons. The core emission is nearly independent of the pH, whereas the shell luminescence increases in the 3-11 pH range, resulting in a cross-readout-free ratiometric response as strong as 600%. In vitro microscopy demonstrates that the ratiometric response in biologic media resembles the precalibralation curve obtained through far-field titration experiments. The NCs show good biocompatibility, enabling us to monitor in real-time the pH in living cells. English WILEY-V C H VERLAG GMBH IN-BULK NANOCRYSTALS CDTE QUANTUM DOTS SEMICONDUCTOR NANOCRYSTALS COLORIMETRIC ASSAY DUAL EMISSION CANCER-CELLS INTERFACE DYNAMICS SENSOR FIXATION Two-Color Emitting Colloidal Nanocrystals as Single-Particle Ratiometric Probes of Intracellular pH Article 10.1002/adfm.201605533 1 ADVANCED FUNCTIONAL MATERIALS, v.27, no.12 ADVANCED FUNCTIONAL MATERIALS 27 12 scie scopus 000397349400010 2-s2.0-85011850830 Chemistry, Multidisciplinary Chemistry, Physical Nanoscience & Nanotechnology Materials Science, Multidisciplinary Physics, Applied Physics, Condensed Matter Chemistry Science & Technology - Other Topics Materials Science Physics Article IN-BULK NANOCRYSTALS CDTE QUANTUM DOTS SEMICONDUCTOR NANOCRYSTALS COLORIMETRIC ASSAY DUAL EMISSION CANCER-CELLS INTERFACE DYNAMICS SENSOR FIXATION bioimaging colloidal quantum dots pH sensing ratiometric sensing two-color emission