Aerosol Jet Printed Surface-Enhanced Raman Substrates: Application for High-Sensitivity Detection of Perfluoroalkyl Substances

Abstract

Printing technologies offer an attractive means for producing low-cost surface-enhanced Raman spectroscopy (SERS) substrates with high-throughput methods. The development of these substrates is especially important for field-deployable detection of environmental contaminants. Toward this end, we demonstrate SERS-based substrates fabricated through aerosol jet printing of silver nanoparticles and graphene inks on Kapton films. Our printed arrays exhibited measurable intensities for fluorescein and rhodamine dyes down to concentrations of 10–7 M, with the highest SERS intensities obtained for four print passes of Ag nanoparticles. The substrates also exhibited an excellent shelf life, with little reduction in fluorescein intensities after 9 months of shelf storage. We also demonstrated the capability of our substrates to sense perfluoroalkyl substances (PFAS), the so-called forever chemicals that resist degradation due to their strong C–F bonds and persist in the environment. Interestingly, the addition of graphene to the Ag nanoparticles greatly enhanced the SERS intensity of the perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) molecules under basic conditions (pH ∼ 9) compared to that of fluorescein and rhodamine. We were able to successfully detect SERS spectra from nano- and picomolar (∼0.4 ppt) concentrations of PFOA and PFOS, respectively, demonstrating the viability of deploying our SERS sensors in the environment for the ultrasensitive detection of contaminants.

Analysis of needs for enforcement of PFAS in articles and chemical products

“…The fabricated superstructure array offers superior characteristics for the quantitative analysis of luorescent PFOA with a wide detection range from 11 ppb to 400 ppm. PFOS can also be analysed using SERS (Huang et al, 2022;McDonnell et al, 2022). McDonnel et al used aerosol jet printing technologies to produce SERS substrates made of Ag nanoparticles and graphene inks at low-cost and high throughput (Huang et al, 2022;McDonnell et al, 2022).…”

“…PFOS can also be analysed using SERS (Huang et al, 2022;McDonnell et al, 2022). McDonnel et al used aerosol jet printing technologies to produce SERS substrates made of Ag nanoparticles and graphene inks at low-cost and high throughput (Huang et al, 2022;McDonnell et al, 2022). The substrate has an excellent shelf life (9 months) and was successfully used to sense PFAS.…”

Aerosol‐Jet Printed Sensors for Environmental, Safety, and Health Monitoring: A Review

“…[ 262 ] Using these SERS sensors, detection of environmentally pervasive pollutants (i.e., perfluoroalkyl substances (PFAS)) has been achieved at concentration levels as low as 0.4 ng L −1 , much lower than the trace detection values defined by the U.S. Environmental Pollution Agency (70 ng L −1 ). [ 262 ]…”

“…With these considerations in mind, via AJP McDonnell et al recently fabricated SERS-based substrates by depositing graphene and silver nanoparticle inks on polyimide. [262] Using these SERS sensors, detection of environmentally pervasive pollutants (i.e., perfluoroalkyl substances (PFAS)) has been achieved at concentration levels as low as 0.4 ng L −1 , much lower than the trace detection values defined by the U.S. Environmental Pollution Agency (70 ng L −1 ). [262]…”

Beyond the Visible: A Review of Ultraviolet Surface-Enhanced Raman Scattering Substrate Compositions, Morphologies, and Performance

“…Detecting environmentally or militarily relevant analytes, including water and soil contaminants, chemical warfare agents, and explosive compounds, has been explored with visible and UV-SERS [45,[88][89][90]. Compared to visible wavelengths, UV excitation affords increased Raman scattering intensities, mitigation of PL interference, and higher spatial resolution (see Section 2.1).…”