Investigation of fluorophores for single-molecule detection of anodic corrosion redox reactions

Reduction reactions at metal/non-aqueous interfaces can be sensed with the turn-on fluorophore resazurin

“…These results suggest that resazurin is an effective iron corrosion turn-on probe in ethanol-based environments with Z5% v/v water for the concentrations and instrumentation used. Future work could pursue lower limit of detection methods such as single-molecule microscopy 15,18 to determine if no changes were observed at 1% and 3% H 2 O either due to the detection limit of the fluorometer or absence of corrosion taking place (no dye turn on).…”

“…Other fluorophores can be used to detect the oxidation half of reactions, such as dyes which turn-on upon chelation to the oxidation product or undergo oxidation itself. 14,18 The use of resazurin turn-on as a tool to monitor redox reactions has been useful, but largely limited to aqueous environments.…”

Exploring chemistry with single-molecule and -particle fluorescence microscopy

“…This slow diffusion enables their imaging by fluorescence microscopy. Insights into fluid cracking catalysis using catalytic zeolite particle systems [13,14] and corrosion detection on iron cathodes [15,16] are example systems where unique insight has been obtained. The spatiotemporal resolution of fluorescence microscopy provides exquisite 2D and 3D reactivity maps of the location of catalytic reactions on and within these catalytic inorganic materials [11,[17][18][19][20][21][22][23].…”

“…In organic solvents [3,44] Under air-free conditions (glovebox setup and adding solid reagents during imaging) [4,5] Imaging in flow cells [9,32,52] Higher temperature imaging (diffusion at 135°C, chemical reaction at 45°C) [24,52] Types of reactions and processes imaged Hydrolysis [6] Proton-transfer [53] Epoxidation [26,33] Solubilization [4,36] Deallylation [5] Redox (nanoparticle and photocatalysis) [10,11,17,[19][20][21]54] Cross-coupling [46] Oligomerization [14] Polymerization [40][41][42]55] Hydrogenation [56] Cycloaddition [47][48][49][50] Condensation [34,57] Corrosion [15,16] Molecular metal-ligand exchange/dissociation [37][38][39]44] Oxidative addition [4,35,46] Mechanistic questions answered Identification of previously unknown organic and organometallic intermediates …”

Tracking of Protein Adsorption on Poly(l-lactic acid) Film Surfaces: The Role of Molar Mass

“…Protein adsorption has been extensively studied using various sensitive techniques such as quartz crystal microbalance, mass spectrometry, sum frequency generation spectroscopy, Fourier transform infrared spectroscopy, fluorescence correlation spectroscopy, isothermal titration calorimetry, and atomic force microscopy (AFM). ,, These techniques have greatly contributed to our understanding of protein adsorption. – Recently, total internal reflection fluorescence microscopy (TIRFM) has emerged as a powerful tool for studying the dynamics of fluorescent species in different environments at a spatial resolution of approximately 10 nm and a temporal resolution of a few milliseconds. – By combining TIRFM with a highly sensitive camera, this technique can exploit the evanescent field to illuminate fluorescent molecules within 100 nm of the interface. This makes it very suitable for studying the diffusion and adsorption of polymers, peptides, and proteins in ultrathin films, on lipid bilayers, , at interfaces, – during chemical reaction, and for quantifying the spatial/temporal heterogeneity upon protein adsorption. ,– …”