Abstract
<jats:p>The detection of biologically relevant metabolites, such as uric acid (7,9dihydro-1H-purine-2,6,8(3H)-trione), is crucial for the early diagnosis and management of metabolic disorders, including gout and hyperuricemia. However, current sensing platforms often suffer from limitations in sensitivity, selectivity, and cost-effectiveness. In this context, while conventional carbon-based nanomaterials have been extensively explored for biosensing applications, emerging sp-hybridized carbon allotropes, such as cyclo[n]carbons, remain largely unstudied. Herein, we report a first-principles investigation of cyclo[n]carbon (Cn, for n = 10, 14, 16, 18), a novel sp-hybridized carbon ring, as a potential optical and electronic sensor for uric acid, employing geometry optimization, non-covalent interaction modeling, and time-dependent density functional theory (TD-DFT) analyses along with computation of band structure and Density of State (DOS and PDOS). Our results demonstrate pronounced electronic rearrangements and red-shifted absorption spectra upon complexation. The Cn–uric acid and (Cn)2–uric acid composite display stronger and broader absorption bands at longer wavelengths compared to both the isolated sensor and the sample (uric acid). This enhanced absorption in the visible region in the composite enables the detection and quantification of uric acid via on-pot spectroscopic measurements. In addition, this composite formation reduces the sensor’s band gap, providing a technological opportunity to design new instrumentation for detecting uric acid using an electronic device. These findings underscore the viability of cyclo[n]carbon as a metal-free, spectroscopically responsive and electronically responsive platform for uric acid sensing and exemplify how computational chemistry can expedite the rational design of advanced molecular sensors for biomedical applications.</jats:p>