Dual functions of metal ion detection and antibacterial activity of sulfur quantum dots

Abstract

The present investigation deliberates the hydrothermal synthesis of PVA-stabilized sulfur quantum dots (SQDs) with promising luminescence properties (quantum yield: 11%) and smaller particles (4.16±1.2 nm) with strong hydrophilicity, improved dispersion,...

Sensing nitrophenols and luminescent ink applications of sulfur quantum dots

“…Two bands were found at 274 and 342 nm, corresponding to the n–π* and S x 2− transitions. 43 The consistency of the 342 nm absorption and excitation energy peak illustrates that the luminescence may originate from the sulfur core lattice structure. This complete surface passivation and excitation-independent behavior could be a possible reason for the high quantum yield of SQDs.…”

“…Also, the binding energy peaks at 166.4 and 167.69 eV may be attributed to the SO 3 − (2p 2/3 ), SO 2 2− (2p 1/1 ) or SO 3 2− (2p 2/3 ). 42–44 The deconvoluted N 1s spectrum indicated binding energies of 399.88, 397.67 and 400.32 eV (Fig. 1d), which might correspond to the S–N, C–N and N–H functional groups, respectively.…”

“…The entire information elucidated that the synthesized SQDs were crystalline in nature and monoclinic crystal systems with chemical formulae of S 8 . 43…”

“…SQDs are reported as promising fluorescence compounds with good biocompatibility, hydrophilicity, biocompatibility, and surface chemistry. 43 It is worth noticing that the emission property of SQDs was changed significantly in the presence of 2- and 4-nitrophenols. First, the selectivity of SQDs against various analytes such as ascorbic acid (AA), bisphenol A (BPA), catechol (CTC), glucose (Glu), hydroquinone (HQ), resorcinol (RSL), 2-nitrophenol (2-NP), 4-nitrophenol (4-NP), Ag( i ), Al( iii ), Bi( iii ), Ca( ii ), Ce( iii ), Fe( ii ), Fe( iii ), Hg( ii ), Cr( vi ), K( i ), Mn( vii ), Mg( ii ), Na( i ), and Zn( ii ) was evaluated to test the sensing ability of SQDs (Fig.…”

“…The lack of significant or gradual change in the lifetime of SQDs demonstrated that the quenching mechanism might be more static than other types, which may be due to the complex formation or interaction of SQDs with nitrophenols in the ground state. 43…”