Pt-Black-Modified (Hemi)spherical AFM Sensors: In Situ Imaging of Light-Driven Hydrogen Peroxide Evolution.
Andreas HellmannGregor NeusserSven DabossMohamed M ElnagarJohannes LiessemDariusz MitorajRadim BeranekStéphane ArbaultChristine KranzPublished in: Analytical chemistry (2024)
In this work, we present (hemi)spherical atomic force microscopy (AFM) sensors for the detection of hydrogen peroxide. Platinum-black (Pt-B) was electrodeposited onto conductive colloidal AFM probes or directly at recessed microelectrodes located at the end of a tipless cantilever, resulting in electrocatalytically active cantilever-based sensors that have a small geometric area but, due to the porosity of the films, exhibit a large electroactive surface area. Focused ion beam-scanning electron microscopy tomography revealed the porous 3D structure of the deposited Pt-B. Given the accurate positioning capability of AFM, these probes are suitable for local in situ sensing of hydrogen peroxide and at the same time can be used for (electrochemical) force spectroscopy measurements. Detection limits for hydrogen peroxide in the nanomolar range (LOD = 68 ± 7 nM) were obtained. Stability test and first in situ proof-of-principle experiments to achieve the electrochemical imaging of hydrogen peroxide generated at a microelectrode and at photocatalytically active structured poly(heptazine imide) films are demonstrated. Force spectroscopic data of the photocatalyst films were recorded in ambient conditions, in solution, and by applying a potential, which demonstrates the versatility of these novel Pt-B-modified spherical AFM probes.
Keyphrases
- hydrogen peroxide
- atomic force microscopy
- single molecule
- electron microscopy
- high speed
- high resolution
- nitric oxide
- living cells
- label free
- ionic liquid
- room temperature
- gold nanoparticles
- fluorescence imaging
- small molecule
- low cost
- molecular docking
- machine learning
- air pollution
- highly efficient
- single cell
- tandem mass spectrometry
- risk assessment
- big data
- quantum dots
- monte carlo
- solid state