Low cost referenced luminescent imaging of oxygen and pH with a 2-CCD colour near infrared camera

Abstract

A low cost imaging set-up for optical chemical sensors based on NIR-emitting dyes is presented. It is based on a commercially available 2-CCD colour near infrared camera, LEDs and tailor-made optical sensing materials for oxygen and pH. The set-up extends common ratiometric RGB imaging based on the red, green and blue channels of colour cameras by an additional NIR channel. The hardware and software of the camera were adapted to perform ratiometric imaging. A series of new planar sensing foils were introduced to image oxygen, pH and both parameters simultaneously. The used NIR-emitting indicators are based on benzoporphyrins and aza-BODIPYs for oxygen and pH, respectively. Moreover, a wide dynamic range oxygen sensor is presented. It allows accurate imaging of oxygen from trace levels up to ambient air concentrations. The imaging set-up in combination with the normal range ratiometric oxygen sensor showed a resolution of 4-5 hPa at low oxygen concentrations (<50 hPa) and 10-15 hPa at ambient air oxygen concentrations; the trace range oxygen sensor (<20 hPa) revealed a resolution of about 0.5-1.8 hPa. The working range of the pH-sensor was in the physiological region from pH 6.0 up to pH 8.0 and showed an apparent pKa-value of 7.3 with a resolution of about 0.1 pH units. The performance of the dual parameter oxygen/pH sensor was comparable to the single analyte pH and normal range oxygen sensors.

Oxygen Sensing Difluoroboron Dinaphthoylmethane Polylactide

“…47–49 These methods can be achieved with fluorescence and phosphorescence lifetime imaging microscopy (FLIM and PLIM) techniques, 50 or even with high-speed cameras. 51 Intensity based measurements are more easily performed with common instrumentation (e.g. fluorescence microscopes or color cameras).…”

Organ‐On‐A‐Chip Platforms: A Convergence of Advanced Materials, Cells, and Microscale Technologies

“…Therefore, OOC platforms with multisensory capability can be realized. Most examples of dual sensor platforms contain one oxygen sensor combined with a probe for another analyte, such as carbon dioxide, pH, and temperature . Recently, chemiluminescents have generated much attention for analyte detection, as light is generated when they react with the analyte of interest.…”

Nanoparticle- and microparticle-based luminescence imaging of chemical species and temperature in aquatic systems: a review

“…The acquired RGB/NIR images can subsequently be split in separate channels for calculations of relevant image ratios using imaging-software. Reprinted from Sensors and Actuators B: Chemical, 237, Koren K., Jakobsen S. L., Kühl M., In-vivo imaging of O 2 dynamics on coral surfaces spray-painted with sensor nanoparticles, 1095-1101, © 2016 Elsevier B.V. (2016), with permission from Elsevier [53] For spatial mapping with OSPs, optical sensor systems rely on imaging analyte concentration-dependent changes in photon emission with camera systems for ratiometric luminescence imaging [31,32,57,58] or for lifetime-based luminescence imaging [55,59,60]. Pure luminescence intensity imaging suffers from various drawbacks.…”