28 Jul Silver keeps drug sensor stable
Drugs can be detected sensitively in blood plasma using a newly developed sensor surface. To achieve this, researchers at the Leibniz Institute of Photonic Technology (Leibniz IPHT) developed stable silver structures that, according to the institute, are significantly more durable than conventional surface-enhanced Raman spectroscopy (SERS) substrates.
Surface-enhanced Raman spectroscopy (SERS) amplifies the characteristic light signals of molecules, enabling the detection of even very low drug concentrations. Blood plasma is considered a particularly challenging sample because proteins and other components can mask these signals. The long-term goal is to establish SERS as a rapid complement to established laboratory methods.
Sulfate stabilizes silver structures
For the new sensor surface, the researchers grew highly branched silver structures on a substrate and stabilized their surface with sulfate ions. These ions control both the growth of the nanostructures and their protection against oxidation. As a result, the SERS substrate delivers reproducible measurement signals while remaining stable for at least seven months under storage conditions.
The team confirmed both the stability of the silver structures and the origin of the signal enhancement using, among other methods, high-resolution X-ray photoelectron spectroscopy at the BESSY II synchrotron radiation facility operated by the Helmholtz-Zentrum Berlin.
Dr. Dana Cialla-May, Aradhana Dwivedi and Dr. Vladimir Sivakov (from left) are developing stable silver surfaces for light-based drug detection at Leibniz IPHT. Photo: Lavinia Meier-Ewert / Leibniz IPHT
Drug detection demonstrated in blood plasma
In the study, the researchers tested the new substrate with five drugs used in cancer treatment and infection therapy, first in water and then in human blood plasma. Following a simple sample preparation step, all compounds could be detected.
According to the research team, the stable SERS substrates could provide the basis for faster therapeutic drug monitoring in the future. However, further work will be required before clinical use. This includes simplifying sample preparation, establishing scalable manufacturing of the sensor surfaces, and developing standardized measurement systems and data analysis methods.
Original publication:
[Dwivedi, J. Dellith, A. Makarova, S. F. El-Mashtoly, J. Popp, V. Sivakov, D. Cialla-May: Sulfate-directed Silver Dendrites with Enhanced Stability for Ultrasensitive SERS-based Therapeutic Drug Monitoring. Advanced Science 2026, e17092. https://doi.org/10.1002/advs.202517092]
Source: www.leibniz-ipht.de
Photo: Lavinia Meier-Ewert / Leibniz IPHT
Caption: Aradhana Dwivedi performs spectroscopic measurements on the newly developed sensor surfaces in the laboratory at Leibniz IPHT.