Highly Sensitive Detection of Silver Ions Enabled by RecJ f Exonuclease Cleavage and Reductant-Mediated Electrochemical Amplification

A facile “off-on” pattern based on one-pot synthesis of N doped carbon dots for sensitive detection of Ag+ and S2O32-

In this work, a new “off-on” fluorescence strategy for determination of Ag+ and S2O32− has been presented. Nitrogen doped carbon dots (N-CDs) were synthesized using oxalic acid dihydrate and ethylenediamine...

Powder carbonization to synthesize novel carbon dots derived from uric acid for the detection of Ag(I) and glutathione

This article first reported that a simple synthesis of carbon dots (UCDs) by pyrolysis of uric acid was proposed. The excitation wavelength was 350 nm and the emission wavelength was 402 nm for the synthesized UCDs. And the corresponding fluorescence quantum yield was 52.06%. The obtained UCDs could be served as a fluorescence probe to recognize Ag⁺ and glutathione (GSH), respectively. The fluorescence of UCDs was quenched after the addition of Ag⁺. The obtained UCDs had a linear relationship with Ag⁺ in the detection range of 0.1 μM to 2.0 μM, and the detection limit was 39 nM. The quenching fluorescence of this system could be restored after adding GSH. The fluorescence intensity increased linearly on increasing the concentration of glutathione in the range of 4 to 9 μM, and the detection limit was 66 nM. Based upon these phenomena, we proposed a novel fluorescence probe to detect Ag⁺ and detect GSH, respectively. In addition, the prepared UCDs were successfully applied to analyze Ag⁺ in mineral waters and GSH in blood serums.

A novel mode of DNA assembly at electrode and its application to protein quantification

Sensitive and specific detection of protein is of great significance for early diagnosis and prognosis of many diseases. However, great challenges remain unsolved including relative low sensitivity, high cost, long testing time, complicated instrument and laborious operation. To improve the performance of protein detection methods, development of fine reaction interface for recognition and signal amplification is of great importance. In this work, we construct a novel mode of DNA assembly at electrode interface based on a tripodal surface anchor and an electrochemical aptasensor for protein assay is developed. The orientation of the immobilized DNA is optimized, which promises the efficiency of protein recognition. In addition, hybridization chain reaction is employed for further signal amplification. Therefore, this detection method shows high sensitivity with excellent specificity. The strategy can be universally applicable by simply modifying the sequences of used DNA probes.

Electrochemical sensing of attomolar miRNA combining cascade strand displacement polymerization and reductant-mediated amplification

An electrochemical biosensor for miRNA assay with attomolar sensitivity was developed based on cascade strand displacement polymerization and reductant-mediated amplification.