A research team led by Prof. ZHANG Hongwen at the Institute of Solid State Physics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, has developed a portable surface-enhanced Raman spectroscopy (SERS) sensor that can rapidly detect trace amounts of sarin and other organophosphorus (OP) nerve agents.
The new sensor uses a specially designed molecular probe to recognize the P–C bond found in OP nerve agents. It can detect sarin in both liquid and gas phases, making it suitable for rapid on-site screening.
The findings were published in Chemical Engineering Journal .
OP nerve agents such as sarin are highly toxic, making rapid detection important for public safety, particularly at airports, border checkpoints and large public events. Current methods, including chromatography-mass spectrometry and ion mobility spectrometry, are accurate but often require bulky equipment and laboratory analysis, limiting their use for rapid on-site detection.
In this study, the researchers combined SERS technology with a molecular probe designed to selectively capture OP agents. The probe, pyridylamidoxime-mercapto (PAOM), contains an oxime group that reacts with the target molecules, while a thiol group helps attach the probe to the gold surface of the SERS chip. A pyridine ring also enhances the Raman signal, making small amounts of the target easier to detect.
The researchers tested three versions of the probe and found that the para isomer, p-PAOM, showed the strongest interaction with OP agents and the lowest reaction energy barrier.
Tests with a portable Raman spectrometer showed that the sensor could detect sarin in liquid samples in less than 20 seconds, with a detection limit of 10 ppb. It also showed good selectivity in the presence of common interfering substances.
The sensor remained effective at temperatures of up to 100 °C and across a pH range of 3 to 12, suggesting that it can be used under a wide range of environmental conditions.
The technology is now being further developed for technology transfer and industrial applications, according to the team.
Chemical Engineering Journal
Rational design of an oxime-functionalized probe for ultrasensitive and portable SERS detection of organophosphorus nerve agents
28-Aug-2026