Wavelengths and Lifetimes of Paper Autofluorescence: A Simple Substrate Screening Process to Enhance the Sensitivity of Fluorescence-Based Assays in Paper

Shah, Kamal G.; Yager, Paul

doi:10.1021/acs.analchem.7b02424

Cited by 45 publications

(34 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Fluorescence has attracted increasing attention for the quantitative measurement of protein amounts since it provides opportunities for multiplexed observations. However, its sensitivity has been limited by the autofluorescence of the transferring membranes 26 : Upon excitation with UV or blue light, these membranes emit significant fluorescence from the blue to the yellow regions of the visible spectrum, which overlaps the emission spectra of the most commonly used fluorescent probes, thereby limiting the reliable detection of targeted proteins to no less than 0.5 ng 36 .…”

Section: Resultsmentioning

confidence: 99%

Macroscale fluorescence imaging against autofluorescence under ambient light

et al. 2018

View full text Add to dashboard Cite

Macroscale fluorescence imaging is increasingly used to observe biological samples. However, it may suffer from spectral interferences that originate from ambient light or autofluorescence of the sample or its support. In this manuscript, we built a simple and inexpensive fluorescence macroscope, which has been used to evaluate the performance of Speed OPIOM (Out of Phase Imaging after Optical Modulation), which is a reference-free dynamic contrast protocol, to selectively image reversibly photoswitchable fluorophores as labels against detrimental autofluorescence and ambient light. By tuning the intensity and radial frequency of the modulated illumination to the Speed OPIOM resonance and adopting a phase-sensitive detection scheme that ensures noise rejection, we enhanced the sensitivity and the signal-to-noise ratio for fluorescence detection in blot assays by factors of 50 and 10, respectively, over direct fluorescence observation under constant illumination. Then, we overcame the strong autofluorescence of growth media that are currently used in microbiology and realized multiplexed fluorescence observation of colonies of spectrally similar fluorescent bacteria with a unique configuration of excitation and emission wavelengths. Finally, we easily discriminated fluorescent labels from the autofluorescent and reflective background in labeled leaves, even under the interference of incident light at intensities that are comparable to sunlight. The proposed approach is expected to find multiple applications, from biological assays to outdoor observations, in fluorescence macroimaging.

show abstract

Section: Resultsmentioning

confidence: 99%

Macroscale fluorescence imaging against autofluorescence under ambient light

et al. 2018

View full text Add to dashboard Cite

show abstract

“…The strip reader readout the ICA signal and the four-parameter logistic curves were fitted to the data according to the method outlined by Holstein 35,36 . The eight-channel test column was composed of a plurality of channels that contain ICA strips.…”

Section: Resultsmentioning

confidence: 99%

Pretreatment-Integration for Milk Protein Removal and Device-Facilitated Immunochromatographic Assay for 17 Items

Qie

Huang

Gao

et al. 2019

Sci Rep

View full text Add to dashboard Cite

Accurate and comprehensive immunochromatographic assay (ICA) data are urgently required in the daily supervision of plants, schools, testing institutions, and law-enforcing departments. Through pretreatment-integration and device-facilitated operation, a quantitative ICA with high sensitivity and throughput was realized on the basis of a commercialized semi-quantitative ICA strip. Three pretreatment methods, namely, acid base, heavy metal salt, and organic solvent methods, have less than three steps. The pretreatment was established for protein removal. A total of 17 pretreated ICA items in milk were considered for the identification of the most suitable pretreatment method. The items are composed of six items pretreated by the acid-base method, six by the heavy salt method, and five by the organic solvent method. Then, the ICA results with pretreatment were compared with those without pretreatment. After pretreatment, the signal intensity increased by 39%, the detection limit decreased to 12%, the half maximal inhibitory concentration decreased to 18%, and the detection range increased fourfold. A device with mixing and centrifugation functions was designed for the pretreatment-related operations. A pre-incubation sampling device was used to facilitate incubation in batch and high-throughput detection. An ICA reader was used. The detection throughput reached 8 samples per batch or 32 samples per hour. The designed devices were printed through 3D printing and rapid prototyping.

show abstract

“…Up until now, what has been discussed were methods practiced to avoid, normalize, or subtract the inherent autofluorescence of paper matrices. In a recent publication done by Shah and Yager [ 89 ], a systematic “autofluorescence index” was proposed using excitation–emission matrices for screening and selecting paper substrates for low autofluorescence when developing assays. Conventionally, primarily and solely spectral overlap is considered between target-induced fluorescence and paper over fluorescence.…”

Section: Addressing Autofluorescencementioning

confidence: 99%

Challenges in paper-based fluorogenic optical sensing with smartphones

Ulep

Yoon

2018

Nano Convergence

View full text Add to dashboard Cite

Application of optically superior, tunable fluorescent nanotechnologies have long been demonstrated throughout many chemical and biological sensing applications. Combined with microfluidics technologies, i.e. on lab-on-a-chip platforms, such fluorescent nanotechnologies have often enabled extreme sensitivity, sometimes down to single molecule level. Within recent years there has been a peak interest in translating fluorescent nanotechnology onto paper-based platforms for chemical and biological sensing, as a simple, low-cost, disposable alternative to conventional silicone-based microfluidic substrates. On the other hand, smartphone integration as an optical detection system as well as user interface and data processing component has been widely attempted, serving as a gateway to on-board quantitative processing, enhanced mobility, and interconnectivity with informational networks. Smartphone sensing can be integrated to these paper-based fluorogenic assays towards demonstrating extreme sensitivity as well as ease-of-use and low-cost. However, with these emerging technologies there are always technical limitations that must be addressed; for example, paper’s autofluorescence that perturbs fluorogenic sensing; smartphone flash’s limitations in fluorescent excitation; smartphone camera’s limitations in detecting narrow-band fluorescent emission, etc. In this review, physical optical setups, digital enhancement algorithms, and various fluorescent measurement techniques are discussed and pinpointed as areas of opportunities to further improve paper-based fluorogenic optical sensing with smartphones.

show abstract

Wavelengths and Lifetimes of Paper Autofluorescence: A Simple Substrate Screening Process to Enhance the Sensitivity of Fluorescence-Based Assays in Paper

Cited by 45 publications

References 22 publications

Macroscale fluorescence imaging against autofluorescence under ambient light

Macroscale fluorescence imaging against autofluorescence under ambient light

Pretreatment-Integration for Milk Protein Removal and Device-Facilitated Immunochromatographic Assay for 17 Items

Challenges in paper-based fluorogenic optical sensing with smartphones

Contact Info

Product

Resources

About