Surfactant‐Enhanced Luminescence Lifetime for Biomolecular Detection on Luminescent Gold Surfaces Decorated with Transition Metal Complexes

Abstract

In the development of sensors based on multimodal detection, luminescent probes are attractive for providing a sensitive signal read-out, based either on intensity, wavelength shift or luminescence lifetime. The implicit simplicity of the devices that can be created is dependent of the judicious design of the multimodal probe. We have used transition metal probes which offer combined versatility due to their electroactive and photoluminescent properties, as well as their sensitivity to local environment. We report the influence of surfactant upon the formation of luminescent surfaces with metal complexes based on ruthenium(II), iridium(III) and osmium(II) bearing surface active groups. The results reveal an enhancement of the luminescence lifetime when a mixed monolayer with surfactant is formed. Characteristically, the luminescence lifetime of the ruthenium tris-bipyridyl complex attached to the gold surface increases from 210 ns to 765 ns in the presence of a fluorinated surfactant. The luminescence signal of the modified gold surfaces is also responsive to bovine serum albumin and fetal bovine serum adsorption, demonstrating interaction of the protein with the metal complex in the presence of the surfactant. The biomolecular interaction with the functionalised surfaces is also evidenced by surface plasmon resonance response.[a] Dr.

Assisted delivery of anti-tumour platinum drugs using DNA-coiling gold nanoparticles bearing lumophores and intercalators: towards a new generation of multimodal nanocarriers with enhanced action

“…49 Nevertheless, the toxicity of each of the drug conjugates is higher than that of the carriers alone. The design offers potential to but does not yet include additional targeting vectors for specic cells or tissues, 4,[25][26][27][28][29] but would potentially benet from gold nanoparticle enhanced permeability and retention in vivo.…”

“…5,[19][20][21][22][23][24] Gold nanoparticles (GNPs) have been shown to be versatile drug-delivery platforms for different drugs, allowing easy conjugation procedures and the possibility of co-loading different functionalizing units, such as targeting vectors or imaging probes to modify and control biodistribution. 4,[25][26][27][28][29] In addition, GNPs are themselves biocompatible, non-toxic and inert; their size and dispersity is easy to control and small GNPs efficiently penetrate cell membranes and can be monitored inside cells using a variety of modalities. [30][31][32] Anionic nanoparticles are perceived to be advantageous for drug delivery, as cationic nanoparticles can disrupt membranes in the cell.…”

Luminescence Lifetime-Based Sensing Platform Based on Cyclometalated Iridium(III) Complexes for the Detection of Perfluorooctanoic Acid in Aqueous Samples

“…The primary ion beam used for ToF-SIMS analysis causes molecular fragmentation of the analyte, and certain species can be identified by their characteristic ions. Because the yield of secondary ions is dependent on several parameters including the surrounding matrix, ToF-SIMS studies may draw conclusions from the presence or absence of peaks as well as large variations (orders of magnitude) in peak intensities; however, a fully quantitative study is possible only under set conditions. , The correct interpretation of peak intensities in this study relies on suitable scaling of the y -axis. Here, all peaks were scaled to the area of the C 3 H 7 NO + peak from the amide group in the IrC 12 complex, which is common to all samples and was present in a suitably high intensity to give reliable scaling.…”

“…Because the yield of secondary ions is dependent on several parameters including the surrounding matrix, ToF-SIMS studies may draw conclusions from the presence or absence of peaks as well as large variations (orders of magnitude) in peak intensities; however, a fully quantitative study is possible only under set conditions. 34,35 The correct interpretation of peak intensities in this study relies on suitable scaling of the y-axis. Here, all peaks were scaled to the area of the C 3 H 7 NO + peak from the amide group in the IrC 12 complex, which is common to all samples and was present in IrC 12 @Au (black) and IrC 12 @Au + PFOA (red), (b) IrC 12 -FSA@Au (green) and IrC 12 @Au + PFOA (red), and (c) IrC 12 -FSA@Au (green) and IrC 12 -FSA@Au + PFOA (blue).…”

“…Iridium-based luminescent probes have long-lived luminescence, in the range of hundreds of nanoseconds, in the visible region, originating from triplet charge transfer states. The iridium luminescence is responsive to the local microenvironment around the metal complex with changes that affect the rigidity of the complex, polarity, aggregation, and access of oxygen. − We have previously anchored cyclometalated iridium complexes on gold solid supports using a thiol active ligand (bpySS), which prevented quenching from the gold surface, and studied the influence of the luminescence signal of the iridium films in the presence of proteins. − Herein, we report the development of a novel solid-state luminescence lifetime-sensing platform for PFOA detection based on cyclometalated iridium complexes bearing lipophilic chains of 6 and 12 carbons, respectively, IrC 6 and IrC 12 (Figure ). The hydrocarbon chains provide lipophilic tentacles on the iridium complex, ideal for inducing aggregates or organized self-assembled structures of the cationic iridium complexes.…”