Moreover, a red-to-yellow colorimetric transition takes place when increasing amount of water is added to the gel, endowing the water detection capability of gel in DMSO.
In this colorimetric assay, yellow MTT 3-[4,5-dimethylthiazol-2-yl]-2,-diphenyltetrazolium bromide, (CALBIOCHEM, Darmstadt, Germany) is reduced to purple formazan by live cells' mitochondrial enzymes [ 67, 68] and the color change can be quantified by measuring the absorbance at certain wavelength.
The probe S4 displayed remarkable colorimetric responses from yellow to orange and yellow to green in the presence of CN− and Cu2+, respectively.
The probe showed remarkable colorimetric response from yellow to red in the presence of CN− and AcO−.
Binding interaction of 4O with CN− ions provides a remarkable colorimetric response from yellow to blue (Δλ = 186 nm), enabling naked-eye sensing without any spectroscopic instrumentation.
A highly Hg2+-selective fluorescence enhancing property (>1.5-fold) in conjunction with a visible colorimetric change from yellow to purple has been observed, leading to a potential fabrication of both "naked-eye" and fluorescence detection of Hg2+.
A dual-function chemosensor for Hg2+ and Zn2+ ions, inspired by the green fluorescent protein (GFP) chromophore, was designed and synthesized, which could specifically recognize Zn2+ through an "OFF ON" fluorescence mechanism due to the restriction of the free rotation of the aryl alkene bond, whilst also producing a selective visible colorimetric response from yellow to pink with Hg2+ ions.
The amount of creatinine in plasma and 24 h urine was determined in nine animals using a commercial kit (Biotechnical; Varginha, Minas Gerais, Brazil) based on a kinetic (two-point) colorimetric method (red-yellow) that employs picrate in an alkaline solution.
A long wavelength emission fluorescent (600 nm) and colorimetric (from pink to yellow) chemosensor with high selectivity for H2PO4− ions was designed and synthesized according to the twisted intramolecular charge transfer (TICT) mechanism.
The synthesized compound as a two-faced chemosensor exhibited remarkable colorimetric responses from red to yellow in the presence of Cu2+ and red to violet in the presence of AcOˉ and CNˉ ions, which could be observed by naked eyes.
The assay with MTT, a yellow water-soluble tetrazolium salt, is a simple colorimetric assay to measure cell cytotoxicity.
