Application of curcumin nanoparticles in a lab-on-paper device as a simple and green pH probe

A novel fluorescence and surface-enhanced Raman scattering dual-signal probe for pH sensing based on Rhodamine derivative

“…In recent years, many optical pH sensors have been developed based on the spectral response of synthesized probes [6][7][8][9]. For instance, fluorescent [9,10] and SERS [11][12][13][14][15] sensors are widely used for the monitoring of pH changes in solutions or live cells with the advantages of high sensitivity, real-time spatial compound imaging and nondamaging detection of targets in living cells or tissues [16,17].…”

Paper-based chemical reaction arrays as an effective tool for geographical indication of turmerics

“…3A, some interactions and reactions clearly changed the colour prole of the original turmeric solutions. Prominent examples include the red colour from basic condition (pH 12), 42 the bright red rosocyanine produced from a wellknown complexation with H 3 BO 3 (produced from B 4 O 7…”

New Functionalities for Paper-Based Sensors Lead to Simplified User Operation, Lower Limits of Detection, and New Applications

“…A wide variety of detection modalities have been applied to 2D PADs. For example, colorimetric assays have been developed to test for amino acids (63), bacteria (35,64), biomarkers for cancer (11), lung (36) and liver (17,65) function, gases (66)(67)(68), infectious diseases (69), ions (37,38,(70)(71)(72), heavy metals (39)(40)(41)(73)(74)(75)(76)(77)(78)(79)(80), small molecules (42,72,74,(81)(82)(83), pH (37,44,84), and proteins (1, 85,86). In all of these cases, complexing agents, nanoparticles, or enzymes were used to generate a visible color change.…”

“…Third, particles can be used to amplify detection signals on PADs, thereby eliminating the need for enzymatic amplification. Over the past few years, there have been many reports of the use of nanoparticles for colorimetric (1, 33,35,39,63,69,74,75,79,81,84,[139][140][141] and electrochemical (4-7, 10, 35, 51, 61, 62, 102, 142, 143) detection on both 2D and 3D PADs. Nanotubes, -rods, or -wires comprised of carbon (60, 61, 87-89, 91, 102, 111, 113), zinc oxide (96), gold (86,142), platinum (144), nickel (144), or copper (144) have been integrated into paper-based sensors to enhance detection.…”