A colorimetric method for the determination of xanthine based on the aggregation of gold nanoparticles

Abstract

We describe a highly sensitive method for the determination of traces of xanthine based on the aggregation of citrate-stabilized gold nanoparticles (AuNPs). It is found that, under optimal conditions of pH, the imide group of xanthine is adsorbed on the surface of the AuNPs, thereby displacing citrate ions. This leads to an aggregation of the AuNPs via hydrogen-bond interactions. As a result, the color of the solution changes from red to blue which can be seen with bare eyes and also can be measured by spectrophotometry. The ratio of the absorbances at 630 nm and 520 nm is linearly related to the concentration of xanthine in the 125 nM to 6.0 μM range (r=0.9988), and the detection limit (3σ/slope) is 23 nM. The method is simple, feasible and fast.

Wet-chemically prepared low-dimensional ZnO/Al2O3/Cr2O3nanoparticles for xanthine sensor development using an electrochemical method

“…For excess XNT levels above the normal range, a number of pathological indicators such as hyperuricemia, tumour hyperthermia, xanthinuria, perinatal asphyxia, pre-eclampsia, leukemia, cerebral ischemia, and gout are recognized in the human body. [3][4][5] The derivatives of XNT (caffeine and theobromine) are found as mild stimulants in drinks such as coffee and tea. To produce high quality foods, the meat of fresh sh is used in food industries.…”

Non‐enzymatic Electrochemical Sensor for the Simultaneous Determination of Xanthine, its Methyl Derivatives Theophylline and Caffeine as well as its Metabolite Uric Acid

“…There are reports of several techniques for the determination of XT, TP and CF including chromatography ,,, spectrophotometry and electrochemical (EC) methods , ,. Of these, EC methods are comparatively simple, low‐priced and requires very less chemical treatment thereby providing rapid analysis.…”

A New Class of Blue‐LED‐Excitable NIR‐II Luminescent Nanoprobes Based on Lanthanide‐Doped CaS Nanoparticles

“…We further employed the Lipo-coated CaS:Ce 3+ ,Er 3+ nanoprobes for detection of ad isease marker,x anthine (XA), which can produce H 2 O 2 through the XA/XA oxidase (XOD) enzymatic reaction (Figure 4a). [16] XA is ap urine base found in most human body tissues and fluids. [16b] Abnormal levels of XA in human serum or urine can be an indicator of perinatal asphyxia, xanthinuria, leukemia, hyperuricemia, and renal failure.…”