3:15 PM - 4:00 PM
▲ [15p-313-5] High-resolution impedance and potential imaging using light-addressable potentiometric sensors for bio-imaging applications
Keywords:Light-addressable potentiometric sensor (LAPS), Impedance and potential imaging, biosensor
Light addressable potentiometric sensors (LAPS) can record surface potentials and impedance with spatial resolution using photocurrent measurements at electrolyte/insulator/silicon field-effect structures. Good lateral resolution was achieved using silicon-on-sapphire (SOS) substrates. To improve the sensitivity of LAPS, the traditional insulator was replaced with an ultra-thin organic monolayer [1].
The capabilities of the technique will be demonstrated with a number of model systems. A SU-8 photoresist pattern on a LAPS substrate was used to assess the resolution. The results show that the resolution obtained using a single photon effect can be improved by reducing the laser wavelength. A two-photon effect was used to achieve submicrometre resolution at a wavelength of 1250 nm.
Surface potential imaging using photocurrent measurements at field-effect structures was validated by studying micropatterns of poly(allylamine hydrochloride) (PAH) and DNA on a PAH template showing the potential of the technique for the interrogation of DNA sensor arrays [1]. The technique has also been used for imaging the impedance of polyelectrolyte microcapsules [2] and the surface charge and impedance of living cells in the cell-surface attachment area [3].
[1] J Wang, Y Zhou, M Watkinson, J Gautrot, and S Krause, Sens. Actuator B-Chem. 209, 230 (2015).
[2] J Wang, I Campos, F Wu, J Zhu, G B Sukhorukov, M Palma, M Watkinson, and S Krause, Electrochim. Acta 208, 39 (2016).
[3] D-W Zhang, F Wu, J Wang, M Watkinson, and S Krause, Electrochemistry Communications 72, 41 (2016).
The capabilities of the technique will be demonstrated with a number of model systems. A SU-8 photoresist pattern on a LAPS substrate was used to assess the resolution. The results show that the resolution obtained using a single photon effect can be improved by reducing the laser wavelength. A two-photon effect was used to achieve submicrometre resolution at a wavelength of 1250 nm.
Surface potential imaging using photocurrent measurements at field-effect structures was validated by studying micropatterns of poly(allylamine hydrochloride) (PAH) and DNA on a PAH template showing the potential of the technique for the interrogation of DNA sensor arrays [1]. The technique has also been used for imaging the impedance of polyelectrolyte microcapsules [2] and the surface charge and impedance of living cells in the cell-surface attachment area [3].
[1] J Wang, Y Zhou, M Watkinson, J Gautrot, and S Krause, Sens. Actuator B-Chem. 209, 230 (2015).
[2] J Wang, I Campos, F Wu, J Zhu, G B Sukhorukov, M Palma, M Watkinson, and S Krause, Electrochim. Acta 208, 39 (2016).
[3] D-W Zhang, F Wu, J Wang, M Watkinson, and S Krause, Electrochemistry Communications 72, 41 (2016).