A novel label-free optical cysteine sensor based on the competitive oxidation reaction catalyzed by G-quadruplex halves

4-Amino-6-hydroxy-2-mercaptopyrimidine capped gold nanoparticles as fluorophore for the ultrasensitive and selective determination of l-cysteine

“…The detection limit obtained for Cys in the present study was compared with the reported papers and are given in Table S1. It can be seen from Table S1, the lowest detection limit was achieved in the present study for Cys by any other methods [9,14,16,[35][36][37][38][39][40][41].…”

Spectral properties and thermal stability of AS1411 G-quadruplex

“…AS1411 DNAzyme can catalyze the H 2 O 2 -mediated oxidation of ABTS, turning it into a green and soluble end-product with maximum absorbance at 421 nm [23]. Fig.…”

“…Previous studies have shown that AS1411-hemin complex is a relatively strong peroxidase-like DNAzyme [21][22][23][24]. AS1411 DNAzyme can catalyze the H 2 O 2 -mediated oxidation of ABTS, turning it into a green and soluble end-product with maximum absorbance at 421 nm [23].…”

“…Since AS1411 binds to Nucleolin with high affinity, it can be used dramatically in diagnostic and cancer therapeutic surveys [16][17][18][19][20]. Moreover, AS1411 G-quadruplex binds to hemin compounds and exhibits significant peroxidase activity, which could be exploited used as a biorecognition-element in some biosensors [21][22][23]. Although much attention has been paid to AS1411 applications, its optical and structural features have not been investigated sufficiently.…”

Highly sensitive fluorogenic sensing of L-Cysteine in live cells using gelatin-stabilized gold nanoparticles decorated graphene nanosheets

“…Especially, L-Cys as a semiessential thiol-containing amino acid, which is most important in peptide and protein synthesis, detoxification, metabolism, and neuronal tissues [5][6][7]. However, a series of disorders could be associated with the problem of L-Cys such as slow growth, muscle and fat loss, hair depigmentation, weakness, edema, skin lesions, liver damage, lethargy, Alzheimer's disease, Parkinson's disease and acquired immune deficiency syndromes [10][11][12]. However, a series of disorders could be associated with the problem of L-Cys such as slow growth, muscle and fat loss, hair depigmentation, weakness, edema, skin lesions, liver damage, lethargy, Alzheimer's disease, Parkinson's disease and acquired immune deficiency syndromes [10][11][12].…”