Applications of capillary electrophoresis with chemiluminescence detection in clinical, environmental and food analysis. A review

This paper reviews the latest developments and analytical applications of chemiluminescence detection coupled to capillary electrophoresis (CE-CL). Different sections considering the most common CL systems have been included, such as the tris(2,2'-bipyridine)ruthenium(II) system, the luminol and acridinium derivative reactions, the peroxyoxalate CL or direct oxidations. Improvements in instrumental designs, new strategies for improving both resolution and sensitivity, and applications in different fields such as clinical, pharmaceutical, environmental and food analysis have been included. This review covers the literature from 2010 to 2015.

Recent advances in affinity capillary electrophoresis for binding studies

The present review covers recent advances and important applications of affinity capillary electrophoresis (ACE). It provides an overview about various ACE types, including ACE-MS, the multiple injection mode, the use of microchips and field-amplified sample injection-ACE. The most common scenarios of the studied affinity interactions are protein-drug, protein-metal ion, protein-protein, protein-DNA, protein-carbohydrate, carbohydrate-drug, peptide-peptide, DNA-drug and antigen-antibody. Approaches for the improvements of ACE in term of precision, rinsing protocols and sensitivity are discussed. The combined use of computer simulation programs to support data evaluation is presented. In conclusion, the performance of ACE is compared with other techniques such as equilibrium dialysis, parallel artificial membrane permeability assay, high-performance affinity chromatography as well as surface plasmon resonance, ultraviolet, circular dichroism, nuclear magnetic resonance, Fourier transform infrared, fluorescence, MS and isothermal titration calorimetry.

Light-emitting diodes for analytical chemistry

Light-emitting diodes (LEDs) are playing increasingly important roles in analytical chemistry, from the final analysis stage to photoreactors for analyte conversion to actual fabrication of and incorporation in microdevices for analytical use. The extremely fast turn-on/off rates of LEDs have made possible simple approaches to fluorescence lifetime measurement. Although they are increasingly being used as detectors, their wavelength selectivity as detectors has rarely been exploited. From their first proposed use for absorbance measurement in 1970, LEDs have been used in analytical chemistry in too many ways to make a comprehensive review possible. Hence, we critically review here the more recent literature on their use in optical detection and measurement systems. Cloudy as our crystal ball may be, we express our views on the future applications of LEDs in analytical chemistry: The horizon will certainly become wider as LEDs in the deep UV with sufficient intensity become available.

A highly sensitive LED-induced chemiluminescence platform for aptasensing of platelet-derived growth factor

In this work, we demonstrated a simple and highly sensitive LED-induced chemiluminescence (LED-CL) platform for aptasensing of proteins. It was based on the fact that fluorescein isothiocyanate (FITC) strongly catalyzed the reaction between luminol and dissolved oxygen under LED irradiation. Using FITC as a new catalytic tag, a highly sensitive sandwich type LED-CL aptasensor was fabricated for quantification of the model protein (platelet-derived growth factor-BB, PDGF-BB). Under optimized conditions, the assay for PDGF-BB was linear from 0.1 nM to 100 nM, and the detection limit was as low as 50 pM, which is better than most of other aptamer-based assays without an amplification procedure. Thrombin, bovine serum albumin, hemoglobin, cytochrome C and adenosine triphosphate showed no obvious interferences for the determination of PDGF-BB. The advantages of high sensitivity and selectivity provided by this LED-CL aptasensor will facilitate its wide application in protein assays.

Reusable light-emitting-diode induced chemiluminescence aptasensor for highly sensitive and selective detection of riboflavin

A novel reusable chemiluminescence aptasensor was developed based on aptamer recognition coupled with light-emitting-diode induced chemiluminescence (LED-CL) detection. The sensing approach was based on the design that the model analyte riboflavin (Rf) in sample solutions was captured by the immobilized aptamers and then eluted simply with alkaline luminol solution to catalyze the CL reaction between luminol and dissolved oxygen under high power LED irradiation. This design allowed a very simple (branch-free) flow way for the CL sensing system. The CL intensity versus the Rf concentration was linear in the range from 0.03 to 5ngmL(-1) with a limit of detection (LOD) down low to 8pgmL(-1). Without renewing the aptamer, the relative standard deviation (RSD) for seven consecutive detections is 2.33%; the sensor also showed good stability without performance deterioration after >100 times use. Up to 10000-fold of K(+), Na(+), Ca(2+), Mg(2+), and Fe(3+), 5000-fold for glucose and bovine serum albumin, 1000-fold of uric acid, 1500-fold of ascorbic acid (added with Fe(3+)), 100-fold of flavin mononucleotide and 200-fold of flavin adenine dinucleotide caused no significant interference with the determination of 0.5ngmL(-1) Rf. The sensor was applied for analysis of Rf in urine and food samples with the recovery of 94-103%. The advantages of reusability, simplicity, high sensitivity and selectivity provided by the LED-CL aptasensor will make it a good alternative tool for biological and food analysis.