pH-independent optical sensing of heparin based on ionic liquid-capped gold nanoparticles

Abstract

A simple pH-independent optical method for the sensing of heparin, as a biomedically important polyionic drug, based on aggregation of gold nanoparticles (AuNPs) is described. The polyanionic heparin induces the aggregation of positively charged ionic liquid stabilized AuNPs, which results in a shift in the surface plasmon band and a consequent color change of the AuNPs from red to blue. The color change was monitored using UV-vis spectrophotometry and image analysis methods. The aggregation was confirmed by transmission electron microscopic measurements. The degree of aggregation was found to be proportional to the concentration of the added heparin, allowing its quantitative detection. The change in the absorbance and color-value has been used to monitor the concentration of heparin. This optical method can quantify heparin as low as 0.010 μg mL(-1) and the calibration is linear for a wide range of concentration.

Probing the modulated formation of gold nanoparticles–beta-lactoglobulin corona complexes and their applications

“…3D). In the current work, we found R/G ratio to be the most sensitive and stable indicator with a high correlation coefficient and thus can serve as a potential responsive indicator for aggregation under the same AuNPs concentration, different from detections with AuNPs using G/(R+G+B) for heparin 74 , R/B for DNA 75 , G-B for Pb 2+ 76 and R for quinidine 77 . AuNPs-β-LG corona complexes in the absence of E. coli and AuNPs in the presence of E. coli both displayed a R/G value similar or lower than 1.4 (Fig.…”

Positively charged imidazolium‐based ionic liquid‐protected silver nanoparticles: a promising disinfectant in root canal treatment

“…The ionic liquid‐protected silver nanoparticles (PC Ag NPs) were prepared according to the procedure described by Hemmateenejad et al . (). In brief; all glassware was placed in 1 : 3 HCl/HNO 3 solution, rinsed with triple distilled water three times; then, 1.0 mL of 0.01 mol L −1 AgNO 3 aqueous solution was added to 20 mL of 6.2 m mol L −1 1‐dodecyl‐3‐methylimidazolium chloride ([C 12 mim][Cl]) aqueous solution, and the solution was stirred vigorously.…”

One-Step Synthesis of Water-Dispersible and Biocompatible Silicon Nanoparticles for Selective Heparin Sensing and Cell Imaging

“…Heparin is a highly negatively charged linear polysaccharide with a variable length that consists predominantly (>70%) of trisulfated disaccharide repeating units. It has been widely used as a major anticoagulant in various clinical diagnostic and therapeutic processes with about half a billion doses applied annually. − Moreover, heparin plays a vital role in regulating of a range of normal physiological and pathological processes such as venous thromboembolism, inflammation, metabolism, immune defense, cell growth and differentiation, and blood coagulation. − On the contrary, the higher dose and prolonged use of heparin often induce adverse effects, such as thrombocytopenia and hemorrhage or other fatal bleeding complication. ,− Therefore, controlling the amount of heparin during surgery especially for postoperative and long-term care patients in anticoagulant therapy is crucially significant. − However, it is still considered to be a challenge to quantitative measurement of heparin due to its natural polydispersity, chemical heterogeneity, lack of fluorescent properties or significant absorbance, and the interference of analogues. , To date, a lot of methods have made great progress in heparin sensing, such as phosphorescence, spectrophotometry and fluorescence methods, and colorimetric assays. , However, more simple, rapid, and accurate detection of heparin with high sensitivity and selectively is still highly desirable.…”