ac7b01903_si_001.pdf (1.42 MB)
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
journal contribution
posted on 2017-07-11, 00:00 authored by Raúl Gotor, Pichandi Ashokkumar, Mandy Hecht, Karin Keil, Knut RurackIn
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.