Gel electrophoresis is a powerful tool in gold nanoparticle (AuNP) research. While the technique is sensitive to the size, charge, and shape of particles, its optimal performance requires a relatively large amount of AuNP in the loading wells for visible detection of bands. We here describe a novel and more sensitive method for detecting AuNPs in agarose gels that involves staining the gel with the common organic fluorophore fluorescein, to produce AuNP band intensities that are linear with nanoparticle concentration and almost an order of magnitude larger than those obtained without staining the gel.

The underlying mechanism of the unusual emissive behavior of [Re(CO)3-1,1bisthiazole-(1,4)-diaminobutane)] bromide (4-BT) has been investigated. Synthesis and spectroscopic characterization of structurally similar isomers ([Re(CO)3-1,1-bis-2-thiazole-(1,4)diaminobutane)] bromide (2-BT) and , location of triplet states, solid state and low temperature spectroscopic measurements, and DFT calculations show that the photophysical properties are not due to photoisomerization as previously hypothesized. The results show that the unusual emissive behavior is not observed in structural isomers, is specific to the previously reported complex, 4-BT, and may arise from vibrational energy relaxation and vibrational cooling.