Vibrational spectroscopy of metal carbonyls for bio-imaging and -sensing

Abstract

Transition metal carbonyls exhibit strong CO absorptions in the 2200-1800 cm(-1) region, which is free of interference from other functional groups. This feature has led to their applications in bio-imaging and -sensing, in particular through mid-IR, Raman and more recently, surface-enhanced Raman spectroscopy (SERS). Their use in mid-IR quantitative sensing based on vibrational intensities, and chemical sensing based on frequency shifts and vibrational lifetimes, is reviewed. Their development for Raman sensing following the breakthrough in SERS highlights the potential of coupling metal carbonyls to plasmonic nanostructures as novel optical materials for SERS-based bio-imaging and -sensing.

Spectroscopic and Electronic Properties of Molybdacarborane Complexes with Non‐innocently Acting Ligands

“…A distinguishing feature of 1 a , b are the vibrations of the carbonyl groups at 2017–2090 cm −1 and 1927/1852 cm −1 (λ exc =532 nm) or 1921 cm −1 and 1849 cm −1 (λ exc =780 nm). Analytical techniques based on Raman spectroscopy have already found application in various fields, like reaction monitoring, biosensing or metalloenzyme characterisation . A recent example also involves carboranes in biological application; a drawback might only be the rather high concentrations of some bioactive substances (100 m m ) which are needed when applied on some cell lines …”

A Water‐Soluble Mn(CO)3‐Based and Non‐Toxic PhotoCORM for Administration of Carbon Monoxide Inside of Cells

“…Fourier Transform Infrared (FT‐IR) imaging is a rapid microspectroscopic method to simultaneously obtain spectral and spatial information of a sample in a micron size domain. In recent years, there is increasing interest for detection of metal carbonyl complexes, especially CORMs in mammalian cells …”

Challenges and opportunities in the development of metal-based anticancer theranostic agents

“…It involves mid-IR (650–3300 cm −1 ) excitation of a particular bond or functional group of the target molecule in the vibrational levels [ 46 , 47 ]. Since most molecules possess vibrational modes lying within mid-IR, this technique can in principle be applied to investigate wide variety of analytes in biological systems [ 47 , 48 ]. It is a relatively safe technique compared to others as it does not require ionizing radiation or high energy photons or particles which may cause unwanted damage to cells or organelles.…”

“…Over the years, various aspects of this technique have been significantly improved. For example, the synchrotron radiation FTIR spectromicroscopy (SR-FTIR SM) allowed imaging of living cells with a spatial resolution in the low micron range [ 46 , 48 ]. Policar, Vessieres, Jaouen and others have successfully applied the SR-FTIR SM technique to image various Re(CO) 3 compounds in a single cell, albeit information on antiproliferative potencies of these compounds was not available [ 48 , 151 , 153–155 ].…”