Luminescent Silole Nanoparticles as Chemoselective Sensors for Cr(VI)

Abstract

Colloidal suspensions of 3-aminopropylmethyl(tetraphenyl)silole nanoparticles can be used as selective chemosensors for carcinogenic chromium(VI) analyte. Methylhydrosilole is functionalized by hydrosilation of allylamine, and the colloid is prepared by the rapid addition of water to a THF solution of the silole. The method of detection is through electron-transfer quenching of the fluorescence of the silole colloid (lambda(em) = 485 nm at 360 nm excitation) by the analytes, with hundred parts per billion detection limits. Stern-Volmer plots are linear up to 10 ppm in the case of chromium, but exhibit saturation behavior near 5-10 ppm for arsenic. Dynamic light scattering experiments and AFM measurements show the particle sizes to be around 100 nm in diameter and dependent on solvent composition, with a particle size dispersity of +/-25%. The fluorescence lifetimes of the silole in solution and colloid are approximately 31 ps and approximately 4.3 ns, respectively, while the silole has a lifetime of 6 ns in the bulk solid. A minimum volume fraction of 80% water is necessary to precipitate the colloid from THF, and the luminescence continues to rise with higher water fractions. Colloids in a pH 7 phosphate-buffered suspension show both higher sensitivity and greater selectivity (100-fold) for CrO4(2-) detection than for other oxoanion interferents, NO3-, NO2-, SO4(2-), and ClO4-.

Aggregation-induced emissions of tetraphenylethene derivatives and their utilities as chemical vapor sensors and in organic light-emitting diodes

“…[1][2][3][4] Luminophoric dyes are usually used as solid films in the real-world applications such as organic light-emitting diodes ͑OLEDs͒. During the process of film formation, the dye molecules aggregate, which often results in a weakening in their emission intensities or even a total quenching of their light emissions.…”

“…[12][13][14][15][16] A number of AIE molecules with different structures have subsequently been developed by various research groups. [1][2][3][4][5][6][7][17][18][19][20][21] Many of these AIE dyes, however, are difficult to prepare, involving multistep reactions under stringent conditions. In this work, we synthesized TPE-based luminophors by a onestep reaction in a one-pot procedure and explored the possibility of utilizing the dyes as chemical sensors and OLED components.…”

Thiomethyl Derivatives of Two Oligo(p-phenylene vinylenes) as New Aggregation-Induced Piezofluorochromic Emitters

“…These materials exhibit luminescent color change as a result of molecular aggregation or stacking. Among them, compounds showing piezochromic properties are drawing special attentions in view of developing functional sensors [5][6][7][8][9], memory chips [10,11], optical switches [12,13], security inks [14], and fluorescent probes [15].…”

“…The cyano groups present in the OPV's and related compounds [2,[9][10][11][12] assist in the formation of a Donor-π-Acceptor (D--A) conjugate system. We expected that the position of the cyano substituent may have an effect on the photoluminescent properties of the OPV's as the cyano substitution at the 1-position of the vinyl groups versus the 2-position will significantly change the length of the -bridge.…”

An Amyloid‐Fibril‐Based Colorimetric Nanosensor for Rapid and Sensitive Chromium(VI) Detection

“…HPLC coupling to cloud-point extraction [12] and ionicliquid extraction [13] techniques have been reported for Cr VI analysis. Electrochemical sensors, [14] enzyme-based biosensors, [15] ionophore-based optical sensors, [16] and luminescent chemosensors [17] have also been developed for Cr VI sensing. Nanoparticle-based Cr VI sensors have also been developed in recent years.…”