Optoelectronic Properties of Diamondoid-DNA Complexes

DNA sensing with engineered nanomaterials can bestow a new platform for single nucleotide identification and sequencing. Nevertheless, understanding the relevant nano-bio interfaces can provide a wealth of information on structures, energetics, and dynamics with a great potential in molecular nanotechnology. Herein, we explore the sensitivity of DNA units, the nucleotides, with a tiny probe, the diamond-like structures known as diamondoids. The probe diamondoid and the target nucleotides interact via hydrogen bonding, forming nano-bio complexes. The binding strengths for these complexes lie between the physisorption and chemisorption, allowing a suitable probe to sense the DNA nucleotides. Besides electronic properties, herein we investigate the optical properties of the nucleotides interacting with a functional diamondoid for the first time by assessing the absorption spectra and the charge dynamics within these complexes. The relative arrangements and bonding characteristics of the diamondoid with the nucleotides strongly influence these properties. Interestingly, we observe charge transfer oscillations between the diamondoid and few nucleotides, while one-way transfer or no charge transfer is observed in other cases. Our results provide a deeper understanding of the inherent electron dynamics of these complexes and can be utilized to design functionalized devices for optical detection. The presented approach can be proven essential in determining the properties of molecular complexes targeted for novel applications in sensing and nanoelectronics.