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Understanding how bacteria adhere to a surface is a critical step in the development of novel materials and coatings to prevent bacteria forming biofilms. Here, surface plasmon resonance (SPR) spectroscopy, in combination with self‐assembled monolayers (SAMs) that have different backbone structures and/or functional groups, is used for the first time to study the initial stages of bacterial adhesion to surfaces (i.e., initial interaction of cells with a surface, a process governed by van der Waals, electrostatic, and hydrophobic interactions). The work highlights SPR spectroscopy as a powerful and unique approach to probe bacterial adhesion in real time. SPR spectral data reveal different kinetics of adhesion for the interaction of two marine bacterial species (Marinobacter hydrocarbonoclasticus and Cobetia marina) to a range of organosulfur SAMs. Furthermore, the extent of adhesion is dependent on the backbone structures and functional groups of the SAMs. The role of extracellular polymeric substances (EPS) in bacterial adhesion is also investigated. Pre‐conditioning experiments with cell‐free culture supernatants, containing planktonic EPS, allow quantification of the amount adsorbed onto surfaces and directly account for the impact of EPS adsorption on bacterial adhesion in the assay. While the physicochemical characteristics of the surfaces play a significant role in determining bacterial cell adhesion for low levels of conditioning by planktonic EPS, greater levels of conditioning by EPS reduce the difference between surfaces.

In situ sum‐frequency‐generation spectroscopy is used for the first time to study changes in molecular orientations in charged biofunctionalized self‐assembled monolayers, in response to an applied electrical potential. The findings presented here unravel the mechanism by which charged biomolecules control biomolecular interactions, for example, protein binding affinities, and lay the foundation for future studies aiming to explore molecular conformational changes in response to electrical stimuli.

Nature provides mechanisms that are able to dynamically control specific and nonspecific interactions between cells and biological surfaces [1,2]. Scientists have long tried to reproduce these dynamic biological events and have recently made an important step in that direction by creating artificial stimuli-responsive surfaces [3][4][5][6][7]. These smart substrates present modulatory surface properties that are able to respond to external chemical/biochemical [8][9][10][11][12], thermal [13][14][15], electrical [16][17][18][19][20], and optical stimuli [21][22][23][24][25][26][27][28][29][30][31]. Due to their dynamic nature such substrates are very appealing for applications in the biomedical field [32]. Progress to date has led to control over biomolecule activity [33] and immobilization of a diverse array of proteins, including enzymes [34] and antibodies [35]. These prior achievements have encouraged researchers to take the challenge of using dynamic surfaces to modulate larger and more complex systems, such as bacteria [36] and mammalian cells [37].Achieving control over surface properties could provide new insights in the understanding of cell behavior and can offer distinct benefits with regard to the development of medical devices. For instance, the modulation of cell attachment and detachment could lead to the prevention of unwanted bacteria fouling on implants, reducing the risk of infections and rejection [38][39][40][41][42]. Furthermore, dynamic surfaces able to present on demand regulatory signals to a cell could provide unprecedented opportunities in studies of cell responses in real-time. Cells in tissues adhere to and interact with their extracellular environment via specialized cell-cell and cell-extracellular

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