Editors’ Choice—Luminescent Oxygen Sensors: Valuable Tools for Spatiotemporal Exploration of Metabolism in In Vitro Systems

Abstract

A common biological theme on Earth is the importance of oxygen, regardless of an organism’s metabolic capabilities. This commonality makes the quantification of O2 essential in understanding life as we know it. There are many sensing methods that enable researchers to measure this important analyte, but not all sensors are compatible with every system. This perspective highlights common O2 sensing formats (and recent innovations) with the goal of guiding the reader toward a sensor choice for their desired application. We emphasize the importance of exploring unfamiliar metabolic processes, commercializing new sensors, and establishing collaborations for maximizing innovation and accelerating discovery.

Persistent Luminescence Nanosensors: A Generalized Optode-Based Platform for Autofluorescence-Free Sensing in Biological Systems

“…To fabricate O 2 -sensitive PLNs, we used the phosphorescent PdTPTBP (em: 800 nm; τ 0 = 356 μs) as the O 2 indicator and the ZGO:Cr 3+ emission as the O 2 -insensitive reference (Figure S20) for time-resolved, ratiometric measurements. Exciting the Pd-chelate results in an electronic transition to S 1 and intersystem crossing to an excited triplet state (T 1 ) causing spin inversion and a forbidden transition back to S 0 the mechanism of phosphorescence. , Molecular O 2 can collide with the dye and quench it, resulting in a lower emission intensity and a lower luminescence lifetime. , This collisional quenching process is typically characterized by the Stern–Volmer relationship (eq S3A). Ratiometric O 2 measurements can be described by a pseudo-Stern–Volmer relationship (eq S3B) by instead plotting the quotient of the ratiometric signal (PdTPTBP/ZGO:Cr 3+ ) at 0 mg/L O 2 by the same ratio at prevailing [O 2 ], giving a linear response (Figure A). , As expected, the pseudo- K sv increases over the measured O 2 range by increasing the delay timea function of the variable luminescence lifetime of PdTPTBP (Figures A and S21).…”

“…Exciting the Pd-chelate results in an electronic transition to S 1 and intersystem crossing to an excited triplet state (T 1 ) causing spin inversion and a forbidden transition back to S 0 �the mechanism of phosphorescence. 39,40 Molecular O 2 can collide with the dye and quench it, resulting in a lower emission intensity and a lower luminescence lifetime. 39,40 This collisional quenching process is typically characterized by the Stern−Volmer relationship (eq S3A).…”

“…39,40 Molecular O 2 can collide with the dye and quench it, resulting in a lower emission intensity and a lower luminescence lifetime. 39,40 This collisional quenching process is typically characterized by the Stern−Volmer relationship (eq S3A). Ratiometric O 2 measurements can be described by a pseudo-Stern−Volmer relationship (eq S3B) by instead plotting the quotient of the ratiometric signal (PdTPTBP/ZGO:Cr 3+ ) at 0 mg/L O 2 by the same ratio at prevailing [O 2 ], giving a linear response (Figure 4A).…”

Review—Structural and Optical Interpretations on Phosphor-Based Optical Thermometry

“…Sensors are essential to many technical breakthroughs as well as our daily life. There are several sensors which is globally developed with high end technology like 2D MXenes and Borophene as Intelligent sensors, 1,2 biosensors for biomedical fields, [3][4][5][6][7][8] 3D printing technology 9 Luminescent oxygen sensors for pre-detection of viral diseases, 10,11 Sensor based heat transfer detection, 12 strain sensors, 13 navigation sensor technology 14 and several luminescent based dosimeters. 15 The current generation witnesses a huge interest in optical temperature sensors due to their salient feature such as low cost, insensitive to electromagnetic interference, wide temperature range and they do not require electrical cable, high spatial resolution, and relatively easier detection, etc.…”