The rapid growth of nanotechnology and spectroscopic techniques has accelerated the development of biosensors with high sensitivity and selectivity. Nanoscale metasurfaces can potentially overcome the limitations of conventional optical methods, such as low responsivity and molecular specificity. One promising approach for analyzing subtle biochemical changes that occur in complex biological phenomena is to use terahertz metasurfaces. Here, the aim is to develop a dual-selective terahertz nanodisc metasurface that enabled precise monitoring of neurotransmitter dynamics in a biomimetic environment. Utilizing functionalized terahertz metasurfaces with nanodisc that mimic biosensory receptors, a biosensor selective for both molecular type and resonant frequency is developed. The sensing platform ensures significantly enhanced sensitivity and specificity by recognizing the intermolecular changes associated with serotonin-nanodisc binding and aqueous surrounding effects. The proposed biosensor can potentially provide an efficient tool for studying complex biochemical interactions, and find application in biomedical diagnostics and neuroscience research.