Application of Plasma-Printed Paper-Based SERS Substrate for Cocaine Detection

Area of Science:

• Analytical Chemistry
• Materials Science
• Spectroscopy

Background:

• Surface-enhanced Raman spectroscopy (SERS) is crucial for on-site illicit drug screening.
• SERS strip performance (accuracy, stability, cost) is key for practical applications.
• Existing SERS substrates face limitations in uniformity and cost-effectiveness.

Purpose of the Study:

• To develop a cost-effective and efficient SERS substrate for illicit drug detection.
• To evaluate the performance of a novel nanogold SERS strip produced via plasma-assisted deposition.
• To compare the developed substrate with commercial SERS alternatives.

Main Methods:

• An atmospheric-pressure plasma-assisted chemical deposition process was employed for one-step nanogold film printing on paper substrates.
• X-ray photoelectron spectroscopy (XPS) was used to analyze the film composition and reduction state.
• Cocaine detection performance was evaluated across various concentrations and compared to commercial SERS substrates.

Main Results:

• The plasma-assisted process yielded an even distribution of nanogold particles.
• XPS confirmed complete gold reduction, and plasma post-treatment reduced carbon content.
• The plasma-printed substrate detected more cocaine-associated bands than commercial substrates, with a detection limit as low as 1 ng/mL.
• High spatial uniformity and significantly lower production cost were demonstrated.

Conclusions:

• The developed plasma-printed nanogold SERS substrate offers superior performance for illicit drug detection compared to commercial options.
• This cost-effective and highly sensitive SERS strip is suitable for prompt and accurate on-site screening.
• The novel fabrication method addresses key limitations of current SERS technologies.