Liquid-core waveguide TCSPC sensor for high-accuracy fluorescence lifetime analysis

Wei, Liping; Tian, Yi; Yan, Wenrong; Cheung, K. K.; Ho, Derek

doi:10.1007/s00216-019-01847-6

Cited by 7 publications

(6 citation statements)

References 42 publications

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“…Figure 6 shows the photoluminescence (PL) with identifiable emission peaks for the annealed thin films prepared by inkjet printing. The porous structure suppresses the emission of our films with very low quantum emission yield and very short emission lifetime [31][32][33]. There are five PL peaks which are independent on the excitation wavelength, λ1∼λ5, at ∼378 nm (gap energy ε1=3.28 eV), ∼420 nm (ε2=2.95 eV), ∼460 nm (ε3=2.71 eV), ∼480 nm (ε4=2.57 eV) and ∼530 nm (ε5=2.35 eV).…”

Section: Resultsmentioning

confidence: 99%

Inkjet printing Ag-TiO₂ thin films with suppressed photoluminescence

Fang

Liu

et al. 2019

Semicond. Sci. Technol.

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With ultraviolet sensitive photochemistry and photoelectric properties, TiO 2 is attractive for applications like photocatalysis, photovoltaic devices, and sunscreen products, among others. By coating Ag on TiO 2 surface, the sensitivity can be extended to visible light, endowing enhanced properties with potential new applications. In this work we inkjet print Ag-TiO 2 films from particle suspensions, and investigate the structure, morphology, Ag distribution and the photoluminescence of the films. It is found that Ag nanoparticles form bridges among TiO 2 particles during the post-annealing. These metallic bridges can transport the excited electrons and suppress the recombination of electrons and holes with the photoluminescence of the film reduced by more than half. The work provides an industrial applicable, low-cost, environment friendly route of preparing Ag-TiO 2 films for attractive photochemistry and photoelectric device applications.

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Section: Resultsmentioning

confidence: 99%

Inkjet printing Ag-TiO₂ thin films with suppressed photoluminescence

Fang

Liu

et al. 2019

Semicond. Sci. Technol.

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“…At the same time, the deep learning enhanced approach using CD emission parameters as introduced here works well across pure solvent mixtures as well as different beverages and does not require specific calibration. With recent studies demonstrating the possibility of building portable time-resolved PL sensors, a more widespread use of compact optical ethanol sensors may become possible.…”

Section: Discussionmentioning

confidence: 99%

Utilizing Deep Learning to Enhance Optical Sensing of Ethanol Content Based on Luminescent Carbon Dots

Döring

Rogach

2022

ACS Appl. Nano Mater.

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Optical sensing methods have shown their potential in measuring environmental properties such as temperatures and sample concentrations, increasing the convenience and speed of such measurements. Carbon dots (CDs) are readily available, easy-to-synthesize, and non-toxic luminescent colloidal nanoparticles that have gained prominence as optical probes in recent years. A disadvantage of CDs used for optical sensing is their broad emission profile, leading to unspecific sensing and a potential overlap of their luminescence with the autofluorescence of the samples. Machine learning approaches can address these shortcomings and greatly enhance sensing accuracy. In this study, CDs were employed as optical probes, while machine learning methods were applied to optimize ethanol content determination in ethanol/water mixtures as well as in alcohol-containing beverages. A simple neural network was used to understand the importance of different optical parameters on sensing, while a modular deep learning model was developed for increased generalizability towards samples with strong autofluorescence. Drawing from multiple input channels, the deep learning model was able to predict ethanol concentrations with a mean absolute error of 0.4 vol % in pure solvents and 6.7 vol % in beverages (beers, wines, and spirits). While CDs are excellent candidates to demonstrate deep learning for optical sensing, the methods discussed in this work are promising for improving chemical sensing using various luminescent materials.

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“…Subsequently, the temporal dispersion as a function of l is investigated. Detailed theoretical analysis is presented in the previous work [30].…”

Section: Lcw-tcspc Microsystem a Lcwmentioning

confidence: 99%

Fully Integrated Liquid-Core Waveguide Fluorescence Lifetime Detection Microsystem for DNA Biosensing

et al. 2019

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Time-resolved fluorescence is a widely adopted technique for DNA detection due to its high sensitivity and selectivity. However, due to stringent requirements on optics and electronics, instrumentation with time-resolved capability is bulky and expensive, prohibiting their use in portable and point-of-care applications. In this work, a fully-integrated DNA biosensor based on liquid-core waveguide (LCW) optics for fluorescence lifetime analysis is presented. The DNA biosensor encompasses all-custom bioassay, optics and electronics into a microsystem, delivering a near sample-to-answer level of integration. Lifetime, rather than intensity, is exploited as the analytical signal from the V-carbazole probe for the first time. Excitation propagation within the LCW is investigated both analytically and in simulations to achieve high excitation rejection and low temporal dispersion, enabling the proposed LCW-based system with much smaller instrumentation size to deliver comparable lifetime measurement accuracy to traditional systems. Detection of DNA down to 15 base pairs at a low detection limit of 1.38 nM demonstrates the high applicability of the proposed biosensor for compact, application-specific, and low-cost diagnostics devices.INDEX TERMS DNA biosensing, fluorescence lifetime detection, liquid-core waveguide, TCSPC, turn-on fluorescent probe.

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Liquid-core waveguide TCSPC sensor for high-accuracy fluorescence lifetime analysis

Cited by 7 publications

References 42 publications

Inkjet printing Ag-TiO₂ thin films with suppressed photoluminescence

Inkjet printing Ag-TiO₂ thin films with suppressed photoluminescence

Utilizing Deep Learning to Enhance Optical Sensing of Ethanol Content Based on Luminescent Carbon Dots

Fully Integrated Liquid-Core Waveguide Fluorescence Lifetime Detection Microsystem for DNA Biosensing

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Liquid-core waveguide TCSPC sensor for high-accuracy fluorescence lifetime analysis

Cited by 7 publications

References 42 publications

Inkjet printing Ag-TiO2 thin films with suppressed photoluminescence

Inkjet printing Ag-TiO2 thin films with suppressed photoluminescence

Utilizing Deep Learning to Enhance Optical Sensing of Ethanol Content Based on Luminescent Carbon Dots

Fully Integrated Liquid-Core Waveguide Fluorescence Lifetime Detection Microsystem for DNA Biosensing

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Product

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Inkjet printing Ag-TiO₂ thin films with suppressed photoluminescence

Inkjet printing Ag-TiO₂ thin films with suppressed photoluminescence