TY - JOUR A1 - Gotor, Raul A1 - Ashokkumar, Pichandi A1 - Hecht, Mandy A1 - Keil, Karin A1 - Rurack, Knut T1 - Optical pH Sensor Covering the Range from pH 0−14 Compatible with Mobile-Device Readout and Based on a Set of Rationally Designed Indicator Dyes N2 - In this work, a family of pH-responsive fluorescent probes has been designed in a rational manner with the aid of quantum chemistry tools, covering the entire pH range from 0−14. Relying on the boron−dipyrromethene (BODIPY) core, all the probes as well as selected reference dyes display very similar spectroscopic properties with ON−OFF fluorescence switching responses, facilitating optical readout in simple devices used for detection and analysis. Embedding of the probes and reference dyes into hydrogel spots on a plastic strip yielded a test strip that reversibly indicates pH with a considerably small uncertainty of ~0.1 pH units. These strips are not only reusable but, combined with a 3D-printed case that can be attached to a smartphone, the USB port of which drives the integrated LED used for excitation, allows for autonomous operation in on-site or in-the-field applications; the developed Android application software (“app”) further simplifies operation for unskilled users. KW - Fluorescence KW - pH measurement KW - BODIPY KW - Smartphone KW - Test strip PY - 2017 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-422571 SN - 0003-2700 SN - 1520-6882 VL - 89 IS - 16 SP - 8437 EP - 8444 PB - American Chemical Society CY - Washington, D.C., USA AN - OPUS4-42257 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Radunz, Sebastian A1 - Tschiche, Harald Rune A1 - Moldenhauer, Daniel A1 - Resch-Genger, Ute T1 - Broad range ON/OFF pH sensors based on pKa tunable fluorescent BODIPYs N2 - A set of highly fluorescent, pH-responsive boron dipyrromethene dyes covering the pH range of 5-12 is presented for broad range pH measurements in mixed aqueous-organic median and polymer matrices. Readout in the intensity Domain with low cost and miniaturized Instrumentation utilizes reversible protonation induced switching ON of their initially completely quenched flourescence mediated by photoinduced electron Transfer. All dyes, rationally designed to reveal closely matching Absorption and Emission properties, are accessible via facile two-step reactions in Overall yields of up to 20%. By modifying the Substitution pattern of the meso-Aryl substiuent, the pKa values could be fine-tuned from 6 to 11. Integration of these molecules into polymeric films by a simple mixing procedure yielded reversible and longterm stable pH sensors for naked eye detection. KW - Fluorescence KW - Sensor KW - PH KW - Dye KW - BODIPY KW - Synthesis KW - Quantification KW - Film KW - Quantum yield KW - Lifetime KW - PET PY - 2017 U6 - https://doi.org/10.1016/j.snb.2017.05.080 SN - 0925-4005 VL - 251 SP - 490 EP - 494 PB - Elsevier AN - OPUS4-41782 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -