Colorimetric absorbance mapping and quantitation on paper-based analytical devices

Soda, Yoshiki; Robinson, Kye J.; Cherubini, Thomas; Bakker, Eric

doi:10.1039/d0lc00028k

Cited by 42 publications

(18 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…While colorimetric absorbance data from commercial PCIs also show a UV-C dose response (S4 Fig), the unknown chemical composition of the commercial PCIs confounds determination of reaction parameters. Colorimetric absorbance of dye on paper has been found to deviate from Beer's Law [25], so careful calibration of colorimetric absorbance over a range of known dye concentrations is required to quantify concentrations or reaction kinetics from colorimetric absorbance on paper [30]. Nevertheless, adoption of colorimetric absorbance approaches will be useful to inform design of new optimized chemistries for PCI materials.…”

Section: Novel Pci Quantification Accurately Assesses Spatial Nonunifmentioning

confidence: 99%

Quantitative UV-C dose validation with photochromic indicators for informed N95 emergency decontamination

et al. 2021

View full text Add to dashboard Cite

With COVID-19 N95 shortages, frontline medical personnel are forced to reuse this disposable–but sophisticated–multilayer respirator. Widely used to decontaminate nonporous surfaces, UV-C light has demonstrated germicidal efficacy on porous, non-planar N95 respirators when all surfaces receive ≥1.0 J/cm2 dose. Of utmost importance across disciplines, translation of empirical evidence to implementation relies upon UV-C measurements frequently confounded by radiometer complexities. To enable rigorous on-respirator measurements, we introduce a photochromic indicator dose quantification technique for: (1) UV-C treatment design and (2) in-process UV-C dose validation. While addressing outstanding indicator limitations of qualitative readout and insufficient dynamic range, our methodology establishes that color-changing dosimetry can achieve the necessary accuracy (>90%), uncertainty (<10%), and UV-C specificity (>95%) required for UV-C dose measurements. In a measurement infeasible with radiometers, we observe a striking ~20× dose variation over N95s within one decontamination system. Furthermore, we adapt consumer electronics for accessible quantitative readout and use optical attenuators to extend indicator dynamic range >10× to quantify doses relevant for N95 decontamination. By transforming photochromic indicators into quantitative dosimeters, we illuminate critical considerations for both photochromic indicators themselves and UV-C decontamination processes.

show abstract

Section: Novel Pci Quantification Accurately Assesses Spatial Nonunifmentioning

confidence: 99%

Quantitative UV-C dose validation with photochromic indicators for informed N95 emergency decontamination

et al. 2021

View full text Add to dashboard Cite

show abstract

“…This limitation is addressed in the colorimetric method for quantifying accurate absorbance value up to the pixel level through a scanner and smartphone. Accurate and precise data is obtained through the computational process (Soda et al 2020). In another work, a quantitative relationship is determined between the concentration and color data for getting accurate results (Soda and Bakker 2019).…”

Section: Possible Routes To Overcome the Limitations Of µPads For Poctmentioning

confidence: 99%

Nano-functionalized paper-based IoT enabled devices for point-of-care testing: a review

Kishnani

Park

Nakate

et al. 2021

Biomed Microdevices

View full text Add to dashboard Cite

“… 20 − 22 The phone-specific camera issues can be resolved when gamma correction is known. Indeed, removing gamma correction in acquired images produced colorimetric absorbance linearly proportional to the concentration of light-absorbing sources, 23 , 24 which facilitated accurate quantitative assays. Unfortunately, gamma correction is often proprietary and inaccessible, and estimating gamma correction would require measuring camera’s spectral responses to illumination of varying wavelength.…”

Section: Introductionmentioning

confidence: 99%

Normalizing the Optical Signal Enables Robust Assays with Lateral Flow Biosensors

Park

Park²,

Cho

et al. 2022

ACS Omega

View full text Add to dashboard Cite

Lateral flow assays (LFAs) are widely adopted for fast, on-site molecular diagnostics. Obtaining high-precision assay results, however, remains challenging and often requires a dedicated optical setup to control the imaging environment. Here, we describe quick light normalization exam (qLiNE) that transforms ubiquitous smartphones into a robust LFA reader. qLiNE used a reference card, printed with geometric patterns and color standards, for real-time optical calibration: a photo of an LFA test strip was taken along with the card, and the image was processed using a smartphone app to correct shape distortion, illumination brightness, and color imbalances. This approach yielded consistent optical signal, enabling quantitative molecular analyses under different illumination conditions. We adapted qLiNE to detect cortisol, a known stress hormone, in saliva samples at point-of-use settings. The assay was fast (15 min) and sensitive (detection limit, 0.16 ng/mL). The serial qLiNE assay detected diurnal cycles of cortisol levels as well as stress-induced cortisol increase.

show abstract

Colorimetric absorbance mapping and quantitation on paper-based analytical devices

Abstract: A pixel-level colorimetric absorbance analysis can measure the total quantity of dye on paper, irrespective of shape and size.

Cited by 42 publications

References 23 publications

Quantitative UV-C dose validation with photochromic indicators for informed N95 emergency decontamination

Quantitative UV-C dose validation with photochromic indicators for informed N95 emergency decontamination

Nano-functionalized paper-based IoT enabled devices for point-of-care testing: a review

Normalizing the Optical Signal Enables Robust Assays with Lateral Flow Biosensors

Contact Info

Product

Resources

About