In situ hydrazine reduced silver colloid synthesis - Enhancing SERS reproducibility.
Herein we report a novel strategy for the in situ synthesis of the silver colloids for LoC-SERS applications. Silver nanoparticles are obtained in a segmented flow based glass microfluidic chip by the reduction of silver ions with hydrazine in ammonium hydroxide solution. Citrate ions are used as protecting agents. The synthesized nanoparticles are characterized by UV-VIS spectroscopy, SEM and TEM imaging. The SERS performance of the in situ synthesized nanoparticles is tested by using adenine as a test analyte right after the colloid synthesis. Reproducibility is tested by repeating the measurements three times at independent days applying the same measurement conditions. In comparison with nanoparticles synthesized in a conventional strategy i.e. in a large batch, chip synthesized nanoparticles show a better day-to-day and long-term reproducibility, lower detection limits and broader working ranges. The great advantage offered by the in situ synthesized colloids combined with the already proven potential of LoC-SERS for bioanalytics, raises the possibility of the employment of LoC-SERS as a fast and sensitive analytic tool in a plethora of applications.
Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich-Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany; Leibniz Institute of Photonic Technology, Albert Einstein Straße 9, 07745 Jena, Germany.
Vera
V
Dugandžić
Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich-Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany; Leibniz Institute of Photonic Technology, Albert Einstein Straße 9, 07745 Jena, Germany.
Izabella Jolan
IJ
Hidi
Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich-Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany; Leibniz Institute of Photonic Technology, Albert Einstein Straße 9, 07745 Jena, Germany.
Karina
K
Weber
Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich-Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany; Leibniz Institute of Photonic Technology, Albert Einstein Straße 9, 07745 Jena, Germany. Electronic address: dana.cialla-may@leibniz-ipht.de.
Dana
D
Cialla-May
Institute of Physical Chemistry and Abbe Center of Photonics, Friedrich-Schiller University Jena, Helmholtzweg 4, 07743 Jena, Germany; Leibniz Institute of Photonic Technology, Albert Einstein Straße 9, 07745 Jena, Germany.
Jürgen
J
Popp
Adenine; In situ; LoC-SERS; Microfluidic; Silver colloid