Optical Chemical Sensor Using Intensity Ratiometric Fluorescence Signals for Fast and Reliable pH Determination

TY - JOUR

T1 - Optical Chemical Sensor Using Intensity Ratiometric Fluorescence Signals for Fast and Reliable pH Determination

AU - Frankaer, Christian G.

AU - Hussain, Kishwar J.

AU - Dorge, Tommy C.

AU - Sorensen, Thomas J.

PY - 2019/1/25

Y1 - 2019/1/25

N2 - Optical pH sensors enable noninvasive monitoring of pH, yet in pure sensing terms, the potentiometric method of measuring pH is still vastly superior. Here, we report a full spectrometer-based optical pH sensor system consisting of sensor chemistry, hardware, and software that for the first time is capable of challenging the performance of an electrode-based pH meter in specific applications such as biopharmaceutical process monitoring and in single-use bioproduction. A highly photostable triangulenium fluorophore emitting at 590 nm was immobilized in an organically modified silicon matrix that allows for fast time-response by rapid diffusion of water in and out of the resulting composite polymer deposited on a polycarbonate substrate. Fluctuations from the fiber optical sensor hardware have been reduced by including a highly photostable terrylene-based reference dye emitting at 660 nm, thus enabling intensity-based ratiometric readouts. The dyes were excited by 505 nm light from a light emitting diode. The sensor was operational within a pH range of 4.6-7.6, and was characterized and demonstrated to have properties that are comparable to those of commercial pH electrodes considering time-response (t 90 < 90 s), precision (0.03 pH-units), and drift.

AB - Optical pH sensors enable noninvasive monitoring of pH, yet in pure sensing terms, the potentiometric method of measuring pH is still vastly superior. Here, we report a full spectrometer-based optical pH sensor system consisting of sensor chemistry, hardware, and software that for the first time is capable of challenging the performance of an electrode-based pH meter in specific applications such as biopharmaceutical process monitoring and in single-use bioproduction. A highly photostable triangulenium fluorophore emitting at 590 nm was immobilized in an organically modified silicon matrix that allows for fast time-response by rapid diffusion of water in and out of the resulting composite polymer deposited on a polycarbonate substrate. Fluctuations from the fiber optical sensor hardware have been reduced by including a highly photostable terrylene-based reference dye emitting at 660 nm, thus enabling intensity-based ratiometric readouts. The dyes were excited by 505 nm light from a light emitting diode. The sensor was operational within a pH range of 4.6-7.6, and was characterized and demonstrated to have properties that are comparable to those of commercial pH electrodes considering time-response (t 90 < 90 s), precision (0.03 pH-units), and drift.

KW - optical pH sensors

KW - chemical sensors

KW - pH optode

KW - ratiometric

KW - ORMOSIL

U2 - 10.1021/acssensors.8b01485

DO - 10.1021/acssensors.8b01485

M3 - Journal article

C2 - 30592615

SN - 2379-3694

VL - 4

SP - 26

EP - 31

JO - ACS Sensors

JF - ACS Sensors

IS - 1

ER -