Dual-mode detection sensor based on nitrogen-doped carbon dots from pine needles for the determination of Fe and folic acid.

In this study, nitrogen-doped carbon dots (N-CDs) from pine needles were obtained by one-step hydrothermal synthesis without any chemical reagents. The fluorescence quenching and absorbance enhancement of N-CDs occurred when Fe and folic acid (FA) were added. Based on this, the dual-mode detection sensor by fluorescence and ultraviolet-visible (UV-Vis) spectrophotometry for the determination of Fe and FA was established.

A "turn-on" DNA-scaffolded silver-nanocluster probe for detection of tumor-related mRNA.

A novel and "turn-on" DNA-silver nanocluster probe (DNA/AgNCs) was developed that can detect the level of breast tumor-related mRNA markers: cyclin D1 mRNA. The fluorescence of DNA/AgNCs probe rendered a "turn-on" response based on the secondary structure changes induced by the target strand. In the presence of target chain, the fluorescence enhances in a concentration-dependent manner, which enables the quantitative detection of analytes.

A yellow-emitting carbon quantum dot-based fluorescent logic gate for the continuous detection of Au and biothiols.

Yellow-emitting carbon quantum dots, named Y-CQDs, were synthesized from O-phenylenediamine and ethylene glycol a one-pot hydrothermal method. A fluorescent IMPLICATION logic gate for the continuous and "on-off-on" detection of Au and biothiols in tap water at the nanoscale level was constructed based on these QDs. It showed promise in real sample detection and also as a fluorescent ink.

Continuous response fluorescence sensor for three small molecules based on nitrogen-doped carbon quantum dots from prunus lannesiana and their logic gate operation.

In this study, an environmentally friendly and water-soluble nitrogen-doped carbon quantum dots (N-CQDs) with quantum yield (QY) of 8.59% were prepared by one-step hydrothermal synthesis without any chemical reagent using the leaves of prunus lannesiana as precursors. The properties and quality of N-CQDs were investigated by Ultraviolet-visible absorption spectroscopy, infrared spectroscopy, X-ray photoelectron spectroscopy, zeta potential, high-resolution transmission electron microscopy and fluorescence spectroscopy.

Nitrogen-Doped Carbon Quantum Dots from Poly(ethyleneimine) for Optical Dual-Mode Determination of Cu and l-Cysteine and Their Logic Gate Operation.

In this work, nitrogen-doped carbon quantum dots from poly(ethyleneimine) (PQDs) were synthesized by a low-cost and facile one-step hydrothermal method without other reagents. A quantum yield (QY) of up to 23.2% with maximum emission at 460 nm under an excitation wavelength of 340 nm was ascribed to the high nitrogen doping (20.

Highly sensitive spectrofluorimetric determination of trace amounts NADP using Europium ion-doxycycline complex probe.

A new spectrofluorimetric method was developed for determination of trace amount of Coenzyme II (NADP). Using europium ion-doxycycline (DC) as a fluorescent probe, in the buffer solution of pH 8.44, NADP can remarkably enhance the fluorescence intensity of the Eu(3+)-DC complex at lambda=612 nm and the enhanced fluorescence intensity is in proportion to the concentration of NADP.

Determination of heparin using ciprofloxacin-Tb3+ as a fluorescence probe.

A new spectrofluorometric method was developed for the determination of trace amounts of heparin (Hep). Using ciprofloxacin (CIP)-terbium (Tb3+) as a fluorescent probe, in a buffer solution of pH 7.20, Hep can remarkably enhance the fluorescence intensity of the CIP-Tb3+ complex at lambda = 545 nm; also, the enhanced fluorescence intensity the Tb3+ ion is proportional to the concentration of Hep.

Determination of adenosine disodium triphosphate (ATP) using oxytetracycline-Eu3+ as a fluorescence probe by spectrofluorimetry.

A new spectrofluorimetric method was developed for determination of adenosine disodium triphosphate (ATP). We studied the interactions between oxytetracycline (OTC)-Eu3+ complex and adenosine disodium triphosphate (ATP) by using UV-vis absorption and fluorescence spectra. Using oxytetracycline (OTC)-Eu3+ as a fluorescence probe, under the optimum conditions, ATP can remarkably enhance the fluorescence intensity of the OTC-Eu3+ complex at lambda = 612 nm and the enhanced fluorescence intensity of Eu3+ ion is in proportion to the concentration of ATP.

Determination of ATP as a fluorescence probe with europium(III)-doxycycline.

A new spectrofluorimetric method has been developed for the determination of adenosine disodium triphosphate (ATP). We studied the interactions between the doxycycline (DC)-Eu3+ complex and adenosine disodium triphosphate (ATP) by using UV-visible absorption and fluorescence spectra. Using doxycycline (DC)-Eu3+ as a fluorescence probe, under the optimum conditions, ATP could remarkably enhance the fluorescence intensity of the DC-Eu3+ complex at lambda = 612 nm.