Multiplexed analysis combining distinctly-sized CdTe-MPA quantum dots and chemometrics for multiple mutually...

Area of Science:

• Analytical Chemistry
• Materials Science
• Environmental Science

Background:

• Semiconductor quantum dots (QDs) show promise as fluorescent probes for heavy metal monitoring.
• However, QD reactivity can limit selectivity and accuracy in heavy metal analysis.
• Developing selective and accurate methods for simultaneous heavy metal detection is crucial.

Purpose of the Study:

• To develop a multi-point detection strategy using multiple QDs for enhanced selectivity and accuracy in heavy metal analysis.
• To simultaneously discriminate between multiple interfering heavy metal species in the same sample.
• To accurately quantify lead (II), mercury (II), and copper (II) in binary and ternary mixtures.

Main Methods:

• Utilized three different MPA-CdTe QDs (2.5, 3.0, and 3.8nm) with distinct emission wavelengths.
• Employed Principal Component Analysis (PCA) and Partial Least Squares Regression (PLS) for fluorescence data analysis.
• Assayed mixtures of QDs emitting at 549/566, 549/634, and 566/634nm.

Main Results:

• The 549/634nm emitting QDs mixture demonstrated superior discrimination of distinct ions in binary and ternary mixtures.
• Achieved good Root Mean Square Error of Cross-Validation (RMSECV) and R²CV values for binary mixtures (0.01–0.08 mgL⁻¹, 0.74–0.89).
• Obtained good RMSECV and R²CV for Hg(II) (0.06, 0.73 mgL⁻¹) and Pb(II) (0.08, 0.87 mgL⁻¹), and acceptable for Cu(II) (0.02, 0.51 mgL⁻¹) in ternary mixtures.

Conclusions:

• The developed multi-point QD approach effectively resolves binary and ternary mixtures of Pb(II), Hg(II), and Cu(II).
• The method provides accurate quantification for lead (II) and mercury (II).
• The system successfully signals the presence of copper (II), demonstrating its utility in environmental monitoring.