Visible Light Spectroscopy of Liquid Solutes from Femto- to Attoliter Volumes inside a Single Nanofluidic Channel

Fuente: arXiv
Gespeichert in:
Bibliographische Detailangaben
Hauptverfasser: Altenburger, Björn, Fritzsche, Joachim, Langhammer, Christoph
Format: Preprint
Veröffentlicht: 2025
Schlagworte:
Online-Zugang:
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
_version_ 1866915175788969984
author Altenburger, Björn
Fritzsche, Joachim
Langhammer, Christoph
author_facet Altenburger, Björn
Fritzsche, Joachim
Langhammer, Christoph
contents UV-Vis spectroscopy is a workhorse in analytical chemistry that finds application in life science, organic synthesis and energy technologies like photocatalysis. In its traditional implementation with cuvettes, it requires sample volumes in the milliliter range. Here, we show how Nanofluidic Scattering Spectroscopy, NSS, which measures visible light scattered from a single nanochannel in a spectrally resolved way, can reduce this sample volume to the attoliter range for solute concentrations in the mM regime, which corresponds to as few as 105 probed molecules. The connection of the nanochannel to a microfluidic in-and outlet system enables such measurements in continuous flow conditions, and the integrated online optical reference system ensures their long-term stability. On the examples of the non-absorbing solutes NaCl and H2O2, and the dyes Brilliant Blue, Allura Red and Fluorescein, we demonstrate that spectral fingerprints can be obtained with good accuracy and that solute concentrations inside the nanochannel can be determined based on NSS-spectra. Furthermore, by applying a reverse Kramers-Kronig transformation to NSS-spectra, we show that the molar extinction coefficient of the dye solutes can be extracted with excellent agreement with the literature values. These results thus advertise NSS as a versatile tool for the spectroscopic analysis of solutes in situations where nanoscopic sample volumes, as well as continuous flow measurements, are critical, e.g., in single particle catalysis or nanoscale flow cytometry.
format Preprint
id arxiv_https___arxiv_org_abs_2502_20298
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Visible Light Spectroscopy of Liquid Solutes from Femto- to Attoliter Volumes inside a Single Nanofluidic Channel
Altenburger, Björn
Fritzsche, Joachim
Langhammer, Christoph
Chemical Physics
Optics
UV-Vis spectroscopy is a workhorse in analytical chemistry that finds application in life science, organic synthesis and energy technologies like photocatalysis. In its traditional implementation with cuvettes, it requires sample volumes in the milliliter range. Here, we show how Nanofluidic Scattering Spectroscopy, NSS, which measures visible light scattered from a single nanochannel in a spectrally resolved way, can reduce this sample volume to the attoliter range for solute concentrations in the mM regime, which corresponds to as few as 105 probed molecules. The connection of the nanochannel to a microfluidic in-and outlet system enables such measurements in continuous flow conditions, and the integrated online optical reference system ensures their long-term stability. On the examples of the non-absorbing solutes NaCl and H2O2, and the dyes Brilliant Blue, Allura Red and Fluorescein, we demonstrate that spectral fingerprints can be obtained with good accuracy and that solute concentrations inside the nanochannel can be determined based on NSS-spectra. Furthermore, by applying a reverse Kramers-Kronig transformation to NSS-spectra, we show that the molar extinction coefficient of the dye solutes can be extracted with excellent agreement with the literature values. These results thus advertise NSS as a versatile tool for the spectroscopic analysis of solutes in situations where nanoscopic sample volumes, as well as continuous flow measurements, are critical, e.g., in single particle catalysis or nanoscale flow cytometry.
title Visible Light Spectroscopy of Liquid Solutes from Femto- to Attoliter Volumes inside a Single Nanofluidic Channel
topic Chemical Physics
Optics
url https://arxiv.org/abs/2502.20298