A Fast and Easy-To-Go Method for the Preparation of Au Nanocluster and Its Application for Fe(III) Cation Sensing

In this article, we reported the synthesis and characterization of gold nanoclusters (AuNCs) with a diameter of ∼2 nm. A simple method of microwave-assisted reaction was applied here, with L-cysteine as both reducing agent and stabilizer. The resulting AuNCs were analyzed by means of TEM, XPS, DLS, and IR. Their photophysical performance was then analyzed in detail, including UV-vis absorption, emission, quantum yield, and lifetime. Efficient red emission was observed from these AuNCs, originating from ligand-to-metal nanoparticle core charge transfer (LMNCT). This red emission was found quenchable by Fe(III) cations. The corresponding quenching curve and sensing performance were discussed. An effective working region of 0–80 μM with an LOD of 3.9 μM was finally observed. Their quenching mechanism was revealed as Fe(III) energy competing for the LMNCT process. The novelty and advancement of this work is the simple synthesis and impressive sensing performance, including wide working region, good linearity, and selectivity.

Enhanced Ca2+ influx in mechanically distorted erythrocytes measured with 19F nuclear magnetic resonance spectroscopy

We present the first direct nuclear magnetic resonance (NMR) evidence of enhanced entry of Ca2+ ions into human erythrocytes (red blood cells; RBCs), when these cells are mechanically distorted. For this we loaded the RBCs with the fluorinated Ca2+ chelator, 1,2-bis(2-amino-5-fluorophenoxy)ethane-N,N,N′,N′-tetraacetic acid (5FBAPTA), and recorded 19F NMR spectra. The RBCs were suspended in gelatin gel in a special stretching/compression apparatus. The 5FBAPTA was loaded into the cells as the tetraacetoxymethyl ester; and 13C NMR spectroscopy with [1,6-13C]d-glucose as substrate showed active glycolysis albeit at a reduced rate in cell suspensions and gels. The enhancement of Ca2+ influx is concluded to be via the mechanosensitive cation channel Piezo1. The increased rate of influx brought about by the activator of Piezo1, 2-[5-[[(2,6-dichlorophenyl)methyl]thio]-1,3,4-thiadiazol-2-yl]-pyrazine (Yoda1) supported this conclusion; while the specificity of the cation-sensing by 5FBAPTA was confirmed by using the Ca2+ ionophore, A23187.

Structural self-sorting of pseudopeptide homo and heterodimeric disulfide cages in water: mechanistic insights and cation sensing

Water-soluble, multi-component disulfide cages showing a self-sorting behavior and cation sensing ability.

Recent advances in cation sensing using aggregation-induced emission

This review summarizes recent advances in AIE-based chemosensors for the detection of a wide range of metal cations, outlining the various sensing mechanisms and sensing performances such as sensitivity and selectivity of AIE-based chemosensors.

Biliverdin Chiral Derivatives as Chiroptical Switches for pH and Metal Cation Sensing

A series of six optically active derivatives of the bile pigment biliverdin, namely (βS,βʹS)-dimethylmesobiliverdin-XIIIα cyclic esters of linear diols [HO(CH2)nOH] where n = 1-6, have been investigated by vibrational circular...

Scalable approach towards specific and ultrasensitive cation sensing in harsh environmental conditions by engineering the analyte-transducer interface

Affordable and high-performing sensing platforms are becoming increasingly critical for sustainable environmental monitoring and medical diagnostics. Such miniaturized and point-of-care sensing platforms need to overcome the fundamental tradeoff between ultrahigh...

Cation Sensing Capabilities of A Nitrophenyl Cinnamaldehyde Derivative

The cationic chemosensor based on organic compound bearing an aminophenol moiety as a receptor for metal analyte and a cinnamaldehyde moiety as chromophoric fragment has been developed. In this work, we report the colorimetric sensing of nitrophenyl cinnamaldehyde derivative, namely methyl-3-(2-hidroxy-5-nitrophenyl amino)-3-phenylpropanoate, towards a variety of metal cations, such as Cu2+, Fe3+, Ni2+ and Zn2+. The cation sensing abilities of the sensor were observed for Cu2+and Fe3+ with a color change from colorless to pink and faint yellow, respectively, The characteristic UV-Vis spectra changes were observed upon addition of Cu2+and Fe3+ cations. The hypsochromic absorption spectra shifts were obtained, indicating the cations and sensor complexations had formed. A metal-to-ligand-charge-transfer (MLCT) had occurred and the charge density of the sensor changed resulting in appearance of new absorption peaks in the UV-Vis spectra and color changes of the sensor solution upon addition of the Cu2+and Fe3+.