Imprinted Zeolite Modified Carbon Paste Electrode as a Selective Sensor for Blood Glucose Analysis by Potentiometry

Imprinted zeolite modified carbon paste (carbon paste-IZ) electrode had been developed as a sensor to analyze blood glucose content by potentiometry. The used zeolite was Lynde Type A (LTA) that synthesized with a mole ratio of Na2O, Al2O3, SiO2 and H2O of 4:1:1.8:270, respectively while non-imprinted zeolite was prepared with a mole ratio of glucose/Si of 0.0306. Glucose was then extracted from the zeolite framework using hot water (80 °C) to produce imprinted zeolite (IZ). The carbon paste-IZ electrode prepared from activated carbon, paraffin pastilles, and IZ with a mass ratio of 5:4:1 showed the best performance. The modified electrode demonstrated the measurement range of 10–4-10–2 M, the Nernst factor of 29.55 mV/decade, the response time less than 120 s, and the detection limit of 5.62 × 10–5 M. Ascorbic acid, uric acid, urea and creatinine did not interfere on the glucose analysis by potentiometry. Comparison test with spectrophotometry showed an accuracy of (90.7 ± 1.4)% (n = 5), while the application of the electrode to analyze five spiked serum samples showed recovery of (92.2 ± 1.3)% (n = 5). The electrode was stable for up to 9 weeks (168 times usage). Based on its performance, the developed electrode can be applied to analyze glucose in human serum sample and recommended for used in the medical field.

Selective glucose sensing in complex media using a biomimetic receptor

A highly selective receptor, circular dichroism and chiral competition are combined in this versatile method for d-glucose analysis.

Stabilization of Plasma Glucose: The Use of Newer Technology and Pragmatic Laboratory Practice

Background The target values for plasma glucose concentrations for the investigation and diagnosis of diabetes and impaired fasting glucose, and the realization that small incremental changes in glucose concentration increase the risk of adverse events, has led to greater focus on laboratory glucose results. Although analytical methods show acceptable precision, the control of preanalytical error due to the stability of glucose remains problematic. The aim of this study was to compare glucose concentrations in 3 different and commercially available blood tubes, with analysis and storage under current practices and conditions. Methods Blood samples for glucose were obtained from consenting patients attending the Diabetic Clinic at the Royal Victoria Hospital, Belfast. Blood was collected into BD Vacutainer® Barricor™ Lithium Heparin tubes, BD Vacutainer Fluoride EDTA tubes, and Greiner Vacuette® FC-Mix (sodium fluoride/citrate/Na2EDTA) tubes in that order. The Barricor tubes were immediately centrifuged at 4000g for 3 min. All samples were then sent to the Biochemistry Laboratory for analysis on the same day, and again the following day after storage at 4 °C. Results There was no significant difference in mean glucose concentrations between immediately centrifuged Barricor and FC-Mix tubes when analyzed on day 0. Both tube types demonstrated higher mean glucose concentrations than traditional fluoride EDTA (F/EDTA) samples. Conclusions Both immediately separated Barricor and citrated FC-Mix plasma preserve glucose concentrations to the same extent, and better than F/EDTA preservative. These newer technologies involved offer pragmatic solutions to improved glucose analysis, allowing laboratories to choose the best option given the source of their samples.

An enhancement of luminol chemiluminescence by cobalt hydroxide decorated porous graphene and its application in glucose analysis

Here, it was shown that a cobalt hydroxide/porous-graphene nanocomposite (PG/Co(OH)2) has great catalytic capability toward luminol as a chemiluminescence active substrate.