A Three-Dimensional Printed Aptasensor Array for Simultaneous Detection of Bioactive Components and Three Coexisting...

The increasing demand for quality control of natural products necessitates innovative methods that enable the simultaneous detection of bioactive components and hazardous contaminants. This study introduces a three-dimensional (3D) printed aptasensor array utilizing MXene/ZnO@Ag@Au nanocomposites for rapid and concurrent detection of berberine (BBR), aflatoxin B1 (AFB1), ochratoxin A (OTA), and chloramphenicol (CAP) in medicinal herbs. The nanocomposite achieves enhanced surface-enhanced Raman scattering (SERS) performance through the synergistic effects of Ag@Au local surface plasmon resonance (electromagnetic enhancement), ZnO charge transfer (chemical enhancement), and the optimized electromagnetic field distribution enabled by the MXene scaffold. A hydrogel microarray fabricated via 3D printing incorporates 4-nitrobenzenethiol (4-NTP)-labeled SERS nanoprobes and specific aptamers, delivering an enhancement factor of 4.97 × 10⁷, excellent reproducibility (RSD < 3%), and high specificity against structural analogs. Detection limits were 0.45 μg/mL for BBR, 0.46 ng/mL for AFB1, 0.95 ng/mL for OTA, and 0.86 ng/mL for CAP. Principal component analysis confirms that signal variations originate predominantly from specific 4-NTP-aptamer interactions. Recovery rates of 80-120% for 36 real samples were validated by thin-layer chromatography with ultraviolet/fluorescence detection, meeting quality control standards. The portable platform enables on-site analysis within 5 min.