Comparison of aggregating agents for the surface-enhanced Raman analysis of benzodiazepines

Area of Science:

• Analytical Chemistry
• Spectroscopy
• Nanotechnology

Background:

• Benzodiazepines are widely prescribed and frequently detected in toxicological and forensic analyses.
• Current immunoassay methods for benzodiazepine detection lack specificity.
• There is a need for more sensitive and specific screening methods for benzodiazepines.

Purpose of the Study:

• To demonstrate the applicability of surface-enhanced Raman spectroscopy (SERS) for analyzing and detecting benzodiazepines.
• To optimize SERS parameters for trace detection of benzodiazepines and their metabolites in urine.
• To evaluate the effectiveness of different aggregating agents for SERS-based benzodiazepine detection.

Main Methods:

• Urine extracts were mixed with gold nanoparticles and chloride salts (MgCl2, CaCl2, KCl, NaCl) as aggregating agents.
• Surface-enhanced Raman spectroscopy (SERS) was employed for trace detection of benzodiazepines.
• Optimization of SERS parameters, including aggregating agent concentration, was performed.

Main Results:

• SERS enabled the detection of eleven different benzodiazepines and metabolites.
• Magnesium chloride (MgCl2) yielded the lowest limit of detection (2.5 ng/mL) and demonstrated linearity across a wide concentration range.
• The optimal MgCl2 concentration was determined to be 1.67 M.

Conclusions:

• SERS is a viable technique for detecting trace amounts of benzodiazepines in aqueous solutions and toxicological samples.
• The developed SERS method offers improved specificity and sensitivity compared to existing techniques.
• Further application of SERS can enhance toxicological screening and forensic analysis of benzodiazepines.