Switch-on fluorescent strategy based on N and S co-doped graphene quantum dots (N-S/GQDs) for monitoring pyrophosphate ions in synovial fluid of arthritis patients

Abstract

This work reports a facile and effective approach for preparing graphene quantum dots co-doped with nitrogen and sulfur (N-S/GQDs). The proposed method comprised pyrolysis of citric acid with glutathione and dialysis treatment. The fabricated N-S/GQDs exhibited blue luminescence and a high fluorescence quantum yield of 36.3%. N-S/GQDs can be sensitively quenched by Fe 3+ , which was absorbed on the edge of N-S/GQDs through the coordination interaction between Fe 3+ and N, S elements. The subsequent introduction of pyrophosphate ion (PPi) resulted in the recovery of the fluorescence of Fe 3+-quenched N-S/GQDs. The stronger coordination reactivity between Fe 3+ and PPi induced changes in fluorescence. PPi concentration was facilely quantified through the recovered amplitudes of the fluorescence intensities of N-S/GQDs. Under the optimized experimental condition, increased fluorescence intensity showed a linear relationship to PPi concentration (1 μM to 1000μM) in serum samples. Additionally, the proposed method featured sensitive and selectivity for the detection of PPi in synovial fluid, suggesting the potential application for simple and accurate clinical diagnosis of arthritic diseases.

A fluorescent sensor constructed from nitrogen-doped carbon nanodots (N-CDs) for pH detection in synovial fluid and urea determination

“…Although the reacting sources of GSH contained sulfur, the sulfur content of N-CDs was much lower than the reported fluorescent carbon nanomaterial using GSH and CA as sources. 29 The reason for the scarce sulfur content may be due to the addition of PEPA and the passivation process that occurred due to further heating at 200 °C in the fabricating process. Such a process would modify the contents of N-CDs.…”

Biosensors Based on Advanced Sulfur-Containing Nanomaterials

“…Sulfur-doped quantum dots are obtained by doping S atoms into other quantum dots, such as silicon, carbon, phosphorus and graphene quantum dots [ 82 ]. Among sulfur-doped quantum dots, sulfur-doped carbon or graphene quantum dots were the most widely studied in the recent years [ 96 , 97 , 98 , 99 , 100 , 101 ]. This review will focus on sulfur-doped carbon or graphene quantum dots.…”

Recognition of AMP, ADP and ATP through Cooperative Binding by Cu(II) and Zn(II) Complexes Containing Urea and/or Phenylboronic—Acid Moieties

“…Phosphorylated metabolites are involved in biologically relevant processes [ 1 ], such as transport of chemical energy [ 2 ] (adenosine triphosphate, ATP, and pyrophosphate (PPi), signal transduction and transmission [ 3 , 4 , 5 ], activation of platelets [ 6 ], and protein kinases [ 7 ] (adenosine monophosphate, AMP, and adenosine diphosphate (ADP), or DNA replication catalyzed by DNA polymerase, a process in which PPi plays an important role [ 8 , 9 , 10 ]. Thus, the design and synthesis of artificial receptors that bind phosphorylated anions is an important scientific goal with potential application in sensing, optical imaging and in vitro clinical diagnosis [ 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 ]. For instance, pyrophosphate (PPi) is one of the hydrolysis products of ATP and is released in DNA/RNA polymerase reactions [ 20 , 21 ].…”