Plasmonic nanodome array within intravenous drug delivery tubing could prevent medication mistakes.
Researchers from the University of Illinois at Urbana-Champaign (IL, USA) have developed a surface-enhanced Raman spectroscopy (SERS)-based method to monitor the concentrations of drugs within an intravenous (iv.) drip. The team fabricated a plasmonic nanodrome array (PNA) using a plastic substrate integrated with a flow cell that connect in series with iv. drug delivery tubing. They subsequently performed SERS detection on several different drug compounds, including morphine, oxycodone and methadone.
According to the researchers, their system demonstrates dose-dependent SERS signal magnitude, with detection limits of ng/ml, which are well below the dosages typically administered to patients (mg/ml). They were able to demonstrate the pharmaceutical compounds detected did not permanently attach to the PNA surface, which would allow continuous monitoring of any changes in concentration as drugs flow through an iv. tube. The SERS measurements were stable over a longer period, up to 5 days, and showed excellent reproducibility.
Although SERS has been used previously to monitor drug delivery within an iv. drip, integrating it with the PNA surface enhances the Raman signals by around 5×108, allowing improved detection limits.
According to lead researcher, Brian Cunningham, currently combinations of drugs give very complex Raman spectra with overlapping peaks, therefore the team will look at characterizing multi-drug combinations in future, as well as miniaturizing the detection instrument.
Source: Wu HY, Cunningham BT. Point-of-care detection and real-time monitoring of intravenously delivered drugs via tubing with an integrated SERS sensor. Nanoscale DOI:10.1039/C4NR00027G (2014) (Epub ahead of print).