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.