Single Drop Electroanalysis and Interfacial Interactions: Sensitivity versus Limit of Detection^†

Area of Science:

• Electrochemistry
• Materials Science
• Analytical Chemistry

Background:

• Screen-printed electrodes (SPEs) are versatile platforms for electrochemical sensing.
• Carboxylated multiwalled carbon nanotubes (MWCNT-COOH) offer unique surface properties for analyte interaction.
• Accurate quantification of pharmaceutical compounds in complex matrices remains a challenge.

Purpose of the Study:

• To develop a sensitive and reliable single-drop electroanalytical method for detecting pharmaceutically relevant compounds.
• To investigate the role of MWCNT-COOH surface modifications in enhancing analyte detection.
• To validate the method's applicability to real-world pharmaceutical samples.

Main Methods:

• Utilizing screen-printed electrodes (SPEs) modified with carboxylated multiwalled carbon nanotubes (MWCNT-COOH).
• Performing single-drop electroanalytical measurements for acetaminophen, nicotine, ascorbic acid, and NADH.
• Analyzing the influence of polar and nonpolar interactions on sensitivity and detection limits.

Main Results:

• Achieved highly sensitive detection of target analytes within a single drop of solution.
• Demonstrated a wide dynamic range attributed to combined polar/nonpolar interactions with MWCNT-COOH.
• Showcased excellent recovery rates when applying the method to commercial pharmaceutical samples.

Conclusions:

• The developed single-drop electroanalytical method using MWCNT-COOH modified SPEs is effective for sensitive and accurate quantification of key pharmaceutical compounds.
• Analyte interaction with the sensor surface, involving both polar and nonpolar forces, critically influences sensitivity and detection limits.
• This approach holds significant promise for rapid, on-site analysis of pharmaceuticals in various real-world applications.