Optimising electrogenerated chemiluminescence of quantum dots via co-reactant selection

Electrochemiluminescence sensors and forensic investigations: a viable technique for drug detection?

Novel psychoactive substances (NPS) are today considered one of the major ticking public health time bombs in regard to drug abuse. The inability to identify these substances with current screening methods, sees their distribution remain uninterrupted and contributes to the high death rates amongst users. To tackle this problem, it is vital that new robust screening methods are developed, addressing the limitation of those currently in place, namely colour subjectivity and lack of compatibility with the complex matrices these substances may be found within. To this avail, electrochemical methods have been assessed. These low cost and extremely portable sensors have been successfully applied for the direct detection of a broad range of compounds of interest in a range of matrices including, herbal material, commercial drinks and biological fluids (serum, saliva, sweat and urine). With their high versatility, gifted through a significant degree of flexibility in regard to electrode material a range of sensors have to date been reported. In this review the various electrochemical sensors developed to date for NPS detection will be compared and contrasted, with a special focus upon those utilising electrochemiluminescence (ECL) technology.

Anodic Electrochemiluminescence of CdTe Quantum Dots Using Tripropylamine as Coreactant: Size-dependent Effect

The quantum size effect of CdTe quantum dots (QDs) has been one of the targets of extensive research concerning the optical spectroscopy of semiconductors, but little is known about their effects on electrochemiluminescence (ECL) behavior, especially in the anodic potential range. In this present study, water-soluble CdTe QDs with different sizes were synthesized with a microwave-assisted hydrothermal method. Upon electrochemical oxidation of the CdTe QD in the presence of tri-n-propylamine (TPrA) as a coreactant, two ECL signals, called ECL₁ and ECL₂, were observed at potentials corresponding to the oxidation of TPrA (at +0.8 V) and CdTe QDs (at +1.2 V), respectively. The relative intensity of ECL₁ significantly increased with increasing the particle size of CdTe QDs, and disappeared when the particle size was less than 2.4 nm. Upon an anodic potential of +0.8 V, TPrA is oxidized at the electrode surface, where the intermediate radical species like TPrA^•+ radical cation and CdTe QDs^•- radical anion are supposed to be formed to give the excited chemical species of CdTe QDs*. Possible ECL mechanisms are proposed from a view point of thermodynamics.

Electrochemiluminescent sensors as a screening strategy for psychoactive substances within biological matrices

Electrochemiluminescent sensors for point-of-care devices; a screening strategy for the direct detection of hallucinogens within a variety of biological matrices.

‘Cathodic’ electrochemiluminescence of [Ru(bpy)3]2+ and tri-n-propylamine confirmed as emission at the counter electrode

Monitoring emission and potentials at both the working and counter electrodes provides new insight into a proposed cathodic electrochemiluminescence system.

Enhanced anodic electrochemiluminescence of CdTe quantum dots based on electrocatalytic oxidation of a co-reactant by dendrimer-encapsulated Pt nanoparticles and its application for sandwiched immunoassays

A first immunosensor using Fe₃O₄@SiO₂-Pt DENs for carrier separation and signal amplification in the CdTe QD-TPrA anodic ECL system.