Research on nicotinamide adenine dinucleotide concentration detection based on terahertz metamaterials

Designed and fabricated a terahertz metamaterial sensor capable of achieving an EIT-like effect. • Detected NAD at varying concentrations (0.1–500 μmol) using THz-TDS in conjunction with the metamaterial sensor. • Distinguished between NAD and NADH at different concentrations by analysing the enclosed area in radar plots. This study designed and fabricated a terahertz metamaterial sensor for detecting nicotinamide adenine dinucleotide (NAD) at varying concentrations. The sensor is investigated through both simulation and experiment. The top resonator layer and the bottom substrate are made of gold and silicon, respectively. Simulations reveal that the device exhibits an electromagnetically induced transparency - like (EIT-like) effect in its transmission spectrum, featuring a transparency window at 0.762 THz and two transmission valleys at 0.642 THz (Dip 1 ) and 0.894 THz (Dip 2 ). The calculated sensitivities at these three frequencies are 49 GHz/RIU, 68 GHz/RIU, and 63 GHz/RIU, respectively. When NAD solutions with concentrations ranging from 0.1 to 500 μmol were applied to the sensor surface, all three resonance frequencies exhibited concentration-dependent red shifts. Experimental results confirm the feasibility of the proposed metamaterial sensor integrated with terahertz time-domain spectroscopy (THz-TDS) for the rapid, high-sensitivity detection of NAD. This work provides a useful strategy for the rapid and non-destructive detection of trace analytes using terahertz metamaterial sensors. Download: Download high-res image (173KB) Download: Download full-size image