Techniques based on the scanning probe microscopy (SPM) platform are playing a key role in the study of surfaces and interfacial phenomena at the nanoscale for more than 30 years. They are considered fundamental towards the exploration and understanding of fields of science and technology so diverse as chemical reactivity and catalysis, electrochemistry and energy storage or cell biology and membrane trafficking.
Major efforts have been invested to integrate analytical tools into these SPM techniques, aiming at expanding their capabilities, beyond the topographic information. Towards this goal, powerful nanospectroscopic techniques that combine SPM, vibrational spectroscopy and nanomaterials, namely for example Tip-enhanced Raman spectroscopy (TERS), are at the forefront of this trend owing to the rich set of structural and chemical information they provide.
However, it is essential that SPM techniques are able to operate under the experimental conditions that best represents the truly functional environment of the sample, namely live-cells in physiological conditions, chemical and electrochemical measurements in-situ in-operando, etc. This implies, in many cases, the unavoidable presence of liquids. Unfortunately, the current SPM nanospectroscopy techniques struggle to operate reliably in liquid environments, and call for complete new approaches to overcome the current problems that hinder the broad applicability and the full exploitation of their potential.
We have explored the capacity of pipette-based SPM modes, namely scanning ion conductance microscopy (SICM), as a multifunctional imaging technique for the study of surfaces, including live-cells. The uniqueness and versatility of pipette-based probes allowed new methodologies for creating plasmonic probes for nano and microscale enhanced spectroscopy, paving the way to a new series of SPM imaging capabilities and experiments.
