Flow-injection chemiluminescence determination of phentolamine based on its enhancing effect on the luminol–potassium ferricyanide system

A supersensitive biosensor based on MoS2 nanosheet arrays for the real-time detection of H2O2 secreted from living cells

A self-supported MoS₂ nanosheet biosensor for highly sensitive detection of H₂O₂ secreted from live cells.

Disposable electrochemiluminescent biosensor for lactate determination in saliva

An electrochemiluminescence-based disposable biosensor for lactate is characterized. The lactate recognition system is based on lactate oxidase (LOx) and the transduction system consists of luminol. All the needed reagents, luminol, LOx, BSA, electrolyte and buffer have been immobilized by a Methocel membrane placed on the working electrode of the screen-printed electrochemical cell. The measurement of the electrochemiluminescence (ECL) is made possible via a photocounting head when 50 microl of sample is placed into the screen-printed cell with a circular container containing the disposable sensing membrane. The compositions of the membrane and reaction conditions have been optimized to obtain adequate sensitivity. The disposable biosensor responds to lactate after 20 s when two 1 s pulses at 0.5 V are applied to obtain the analytical parameter, the ECL initial rate. The linearized double logarithmic dependence for lactate shows a dynamic range from 10(-5) to 5 x 10(-4) M with a detection limit of 5 x 10(-6) M and a sensor-to-sensor repeatability, as relative standard deviation, RSD, of 3.30% at the medium level of the range. The ECL disposable biosensor was applied to the analysis of lactate in human saliva as an alternative procedure for obtaining the lactate level in a non-invasive way. Interferences coming from components of saliva were studied and eliminated in a simple way that was easy to handle. The procedure was validated for use in human saliva, comparing the results against an enzymatic reference procedure. The proposed method is quick, inexpensive, selective and sensitive and uses conventional ECL instrumentation.

Recent applications of flow-injection and sequential-injection analysis techniques to chemiluminescence determination of pharmaceuticals

A review is presented on the state of the art of the chemiluminescence analysis of pharmaceuticals by the two most relevant automated controlled-flow methodologies--flow-injection analysis (FIA) and sequential-injection analysis (SIA). The current chemiluminometric applications of FIA and SIA in pharmaceutical analysis are discussed with special emphasis on the analytical figures of merit and sample matrix characteristics. The review involving 211 references and covering papers published between 2001 and 2006 is divided into several sections according to the fundamental types of chemiluminescence systems employed.

Applications of the luminol chemiluminescent reaction in analytical chemistry

This critical review discusses the results published between 2000 and 2005 on the development of analytical systems based on the luminol chemiluminescent and electrochemiluminescent reactions. An increasing number of non-specific detection systems based on the enhancing, inhibiting or catalysing effect of a large range of compounds have been published. Possible detected compounds and their concomitant presence in samples are discussed. Chemiluminescent and electrochemiluminescent reactions were also found to merge in biochip and microarray development as a possible substitute to the well-established but hardly quantitative fluorescent detections.