Towards the application of Al₂O₃/ZnO nanolaminates in immunosensors: total internal reflection spectroscopic ellipsometry based evaluation of BSA immobilization

Abstract

Signal enhancement due to multiple reflections in a total internal reflection configuration.

Visible Photoluminescence of Variable-Length Zinc Oxide Nanorods Embedded in Porous Anodic Alumina Template for Biosensor Applications

“…We found that the following layer stack gave satisfactory fit for thickness determination: (i) aluminum substrate had n, k values by Rakić et al [59]; (ii) a fixed 40 nm thickness barrier layer was described by effective values from Bruggeman model [60] with 20% Al and 80% Al 2 O 3 [61]; (iii) for porous PAAO/ZnO/void layer with thickness to be determined by fitting, a fixed effective value n = 1.6 was used; (iv) and, finally, for the 35 nm ZnO layer we used a refractive index value of 1.95 [42]. Typical fitted reflectance spectra along with measured data are shown in Figure 3a,b.…”

“…Recently, ZnO nanostructures have been proposed for biosensing using different readout schemes, including photocurrent measurements [39][40][41], combination of ellipsometry and the surface plasmon resonance [42], UV photoluminescence [43], and others. Different physical mechanisms of molecule interaction with ZnO for biosensing have been described, for example, charge transfer, and hydrophobic and electrostatic interaction between the biomolecule and ZnO surface [44].…”

Affinity Sensors for the Diagnosis of COVID-19

“…Optical ellipsometry-based techniques have great potential to be applied in the design of various immunosensors [ 120 ]. Comparing with other existing methods (ELISA, RT-PCR, indirect fluorescent, western blot) of SARS-CoV detection, the imaging ellipsometry-based approach has established itself as a direct, nondestructive, quick, label-free, simple, and low-cost technique [ 121 ].…”

Total internal reflection ellipsometry for kinetics-based assessment of bovine serum albumin immobilization on ZnO nanowires

“…It was shown that higher sensitivity of this method in case of multilayered ZnO structures have been achieved because of multiple reflections of the light occurring in a total internal reflection mode. Especially it was noticeable for ellipsometric parameter Δ, which under total internal reflection condition depends on the angle of incidence [23,24,25].…”