Highly sensitive paper-based immunoassay using photothermal laser speckle imaging

Recent advances in sensitivity enhancement for lateral flow assay

“…B Principle of thermal contrast for LFA [ 129 ]. C Schematic of the PT-LSI sensor [ 130 ]. (a) A 780-nm light illuminated the NC membrane of LFA.…”

“…NC membrane is composed of randomly oriented nanofibers, so it can be used as a diffusion medium to generate high-contrast speckle patterns. Song et al [ 130 ] developed a photothermal laser speckle imaging (PT-LSI)–based LFA (Fig. 8c ).…”

Advanced Signal-Amplification Strategies for Paper-Based Analytical Devices: A Comprehensive Review

“…Among the types of POC testing, paper-based analytical devices (PADs) have emerged as critical POC biosensors for disease monitoring and diagnostics, particularly in resource-constrained regions, for emergencies, and for in-house healthcare owing to their advantageous features, including simplicity, easy storage, disposability, and portability without relying on external devices [ 5 , 6 , 7 , 8 ]. There are three main classifications for PADs—lateral flow assays (LFAs), dipstick assays, and microfluidic PADs (µPADs) [ 9 ] with diversified signal readout approaches including colorimetry [ 10 ] luminescence [ 11 , 12 ] surface-enhanced Raman scattering (SERS) [ 13 , 14 ], photothermal methods [ 15 , 16 ], photoacoustic methods [ 17 ], and electrochemistry [ 18 , 19 ]. The most common detection approach in PADs is the colorimetric method, which can easily determine the presence of a target through color variations, for recognition even with the naked eye and without complicated instruments [ 20 ].…”

Highly selective sensor for the detection of Hg 2+ ions using homocysteine functionalised quartz crystal microbalance with cross‐linked pyridinedicarboxylic acid

“…A carbon nanotubes‐based sensor also used to detect the HMIs selectively but at micromolar range [7, 8] and single‐walled boron nitride nanotube and triple‐walled boron nitride nanotube‐based biosensor simulation approach capable of detecting zeptogram of mass [9, 10] but need to check the sensitivity and complexity of the fabricated device. Many authors used Au/Ag nanoparticles (NPs) for the selective detection of mercury and other biomolecules, but measurements mainly taken in the laboratory‐based analytical instruments and on‐site detection is not possible [11–27]. The mesoporous silica‐based optical selective detection and removal of Hg 2+ ions using nanocomposite material by Shahat et al [28] is a highly pH‐dependent approach, and lower concentration in the nanomolar range is not possible.…”