Method development for in situ study of marine vanadium peroxidase based on SERS and chemometrics.

Vanadium peroxidases from marine algae are responsible for the production of ozone‐depleting compounds, volatile halogenated organic compounds (VHOC). Due to the impact the release of these compounds has on the global atmospheric and biogeochemical processes, there is an interest within marine sciences in developing analytical methods for studying the various aspects of the VHOC production, particularly in situ. This study aimed to provide new methods towards the development of in situ methods within marine sciences. We demonstrate the use of design of experiments together with orthogonal partial least squares (OPLS) and transposed orthogonal partial least squares (T‐OPLS) to address the qualitative spectral analysis of an enzyme‐buffer system. The measurements were performed with surface‐enhanced Raman spectroscopy (SERS) on vanadium bromoperoxisase from the red algae Corallina officinalis. The chemometric tools used aimed to provide greater insights into how factors such as time, amount of gold nanoparticles and enzyme concentration influence the spectral responses and whether there was any synergy between those factors. The results acquired in this report aim to support future method development of chemometrics within in situ applications in marine sciences. Herein, we demonstrate the use of design of experiments orthogonal partial least squares (OPLS) and its variations to address the qualitative analysis of a multicomponent system. The insight gained by us open up for possibilities in developing in vivo SERS methods combined with chemometrics. T‐OPLS combined with a designed experimental space allows separating relevant signals from a multicomponent matrix, which otherwise can be missed during spectral interpretation and OPLS modelling. [ABSTRACT FROM AUTHOR]