Sensing of iron(III)-biomolecules by surfactant-free fluorescent copper nanoclusters

Copper nanoclusters: designed synthesis, structural diversity, and multiplatform applications

“…In addition to clinical blood tests and attempts to prepare nanomaterial-based sensors, CuNCs have also been extensively applied for ferric ion sensing in water, urine and serum samples based on fluorescence quenching of a sensor signal. 30,135,138,145,148,[245][246][247][248][249] For example, dopamine-protected CuNCs-based biosensor could properly operate in the range of 5-300 μM with LOD 1.2 μM. 148 However, the extensive research in the field resulted in even lower LOD values down to 10 nM when tannic acid (TA)-protected CuNCs were implemented as a sensor.…”

“…Moreover, cytochrome c (Cyt c) is a well-known electron transfer mediator and thus a quencher, and it can quench the PL of CuNCs. 247 However, in the presence of trypsin, the Cyt c hydrolyses into peptide fragments and thus inhibits the quenching of PL from CuNCs. Better sensitivity towards trypsin was achieved when GSH-CuNCs together with Cyt c (LOD 2 ng/mL) 380 and dsDNA-CuNCs (LOD 48 pg/mL) 381 were implemented as fluorometric sensors.…”

“…The LODs of glycoproteins and actin were 2.6 nM and 0.12 μg/mL, respectively. CuNCs-based detection of VEGF165, 383 protamine, 307 ferritin, 247 carcinoembryonic antigen (CEA), 384 prostate-specific antigen (PSA) 385 and human immunoglobulin G (IgG) 357 were also successfully demonstrated…”

Synthesis of Copper Nanocluster and Its Application in Pollutant Analysis

“…The main strategy for turn-on sensors is a signal off-on process that the fluorescence would be quenched in the first place and subsequently recovered via the addition of analyte. Surfactant-free copper nanoclusters were exploited as a turn-on probe for quantification of vitamin C [ 55 ]. In the first step, the fluorescence was quenched by the formation of Fe-Cu NCs conjugate through a static quenching mechanism.…”

Assay developments for detection of biological analytes

“…For example, its reduction property to Fe 2+ , allows for stable coordination with bilirubin [123]. As an octahedral high spin 3d 5 transition metal ion that allows for photo induced electron transfer between energy orbitals, it is able to quench fluorescence [124][125][126][127]. Fe 3+ also coordinates well with the galloyl groups of catechol [128].…”