Y-Shaped Deoxyribonucleic Acid Scaffold Pendulums: A One-Step Electrochemical Sensor.

Summary

This study introduces a Y-shaped DNA molecular pendulum sensor using split aptamers to enable one-step electrochemical detection of small molecules and low-molecular-weight proteins. The stable double-arm configuration provided the broadest dynamic range and strongest signal. It accurately quantified enrofloxacin in diluted milk, artificial urine, and cosmetics (0.001–100 ng/mL) and detected myoglobin by simply changing the recognition strand.

Key Findings

• A Y-shaped DNA pendulum using split aptamers enabled one-step electrochemical detection of small molecules and low-MW proteins.
• The stable two-armed configuration delivered broader detection range and larger signal enhancement than single or flexible double-arm designs.
• Enrofloxacin was quantified in diluted milk, artificial urine, and cosmetics over 0.001–100 ng/mL, meeting EU MRL in milk; myoglobin was detectable by changing the recognition strand.

Clinical Implications

Enables rapid, one-step screening of cosmetic products for antibiotic residues and potential contaminants, supporting quality control, regulatory compliance, and post-market surveillance. Could be adapted for point-of-need diagnostics in dermatology and aesthetic practice.

Limitations

• Validation was performed in diluted and artificial matrices; performance in undiluted, real-world samples requires confirmation.
• Potential matrix interferences, long-term stability, and field-deployable calibration were not fully addressed.

Future Directions

Extend validation to real-world cosmetic products and clinical samples, integrate multiplex targets, and engineer portable devices for point-of-need testing with standardized calibration.