Molecular water accumulation on silica measured by land-contrast interferometry with picometer height resolution

TL;DR

This study employs land-contrast interferometry to measure water film accumulation on silica surfaces with picometer resolution, revealing differences based on surface coatings and implications for biosensor accuracy.

Contribution

It introduces a non-destructive, real-time optical method for measuring molecular water films with picometer precision on silica surfaces.

Findings

Water accumulation rates vary on different silica surfaces.

Water contributes false signals in biosensor measurements.

Land-contrast interferometry achieves picometer resolution.

Abstract

We observed water film accumulation on silica surfaces in the air to 2 picometer resolution using optical land-contrast (LC) interferometry. The land-contrast approach is non-destructive and allows real-time measurement of thickness variation of small molecular films on a surface. Water accumulation rates are observed to be different on bare or protein monolayer coated silica surfaces. This suggests that water contributes false signals to mass-sensitive biosensors for protein microarray.