Phytochemical Profiling, Molecular Docking, ADMET Analysis of Zingiber Officinale Peel Extract for the Biogenic Synthesis of ZnO and Fe-Doped ZnO Nanoparticles with Antibacterial and Photocatalytic Potential

Industrial dye effluents are the predominant source of
water pollution,
while the increasing prevalence of bacterial infections poses a serious
public health threat. Nanoparticles offer promising avenues for addressing
these challenges. Therefore, this study sought to synthesize ZnO (ZNP)
and Fe-doped ZnO (F-ZNP) nanoparticles using Zingiber
officinale peel extract and investigate their antimicrobial
and photocatalytic potential, along with molecular insights into the
antibacterial activity of phytochemicals through in silico studies.
Phytochemical profiling of the Z. officinale peel extract was performed using gas chromatography–mass
spectrometry (GC–MS). The physicochemical characteristics of
the biogenic ZNP and F-ZNP were analyzed using X-ray diffraction (XRD),
scanning electron microscopy (SEM), UV–visible (UV–vis)
spectroscopy, and thermogravimetric and differential thermal (TG/DT)
analyses. In silico analysis of phytochemicals was
performed to assess their interactions with bacterial proteins (GyrB
and FabH) and to predict their pharmacokinetic properties. XRD analysis
confirmed the hexagonal wurtzite structure with a mean crystallite
size of 31.92 nm for ZNP and 23.49 nm for F-ZNP. SEM micrographs revealed
a flake-like morphology with an average particle size of 47 and 35
nm for ZNP and F-ZNP, respectively. UV–vis spectroscopy revealed
absorption edges at 363 and 369 nm, with corresponding band gaps of
3.15 and 3.10 eV for ZNP and F-ZNP, respectively. TG/DT thermographs
demonstrated excellent thermal stability, with minimal weight loss
of only 2.70% for ZNP and 5.21% for F-ZNP up to 800 °C. The dynamic
light scattering technique revealed hydrodynamic diameters of ∼433
nm (ZNP) and ∼422 nm (F-ZNP) with minor aggregation. Zeta potentials
of +7.27 mV (ZNP) and +17.44 mV (F-ZNP) indicated low and improved
colloidal stability, respectively, demonstrating enhanced dispersibility
upon Fe doping. The biogenic ZNP exhibited a moderate methylene blue
degradation rate of 56.24%, while F-ZNP resulted in an outstanding
photocatalytic degradation rate of 91.39% within 120 min. Moreover,
F-ZNP demonstrated excellent photocatalytic reusability, maintaining
a high performance (∼78%) even after three cycles. The biogenic
ZNP and F-ZNP exhibited substantial antibacterial activity against
both Gram-positive and Gram-negative bacterial strains, showing a
zone of inhibition of 10 to 16 mm. These results were corroborated
by favorable binding affinity with bacterial proteins −7.2
to −5.0 kcal/mol), and the bioactive molecules were safe based
on ADMET analysis. Moreover, both ZNP and F-ZNP exhibited excellent
biocompatibility with hemolysis percentages remaining below 2% across
all tested concentrations (25–400 μg/mL). Notably, F-ZNP
demonstrated slightly enhanced hemocompatibility compared to ZNP.
Therefore, our findings suggest a facile and sustainable route to
synthesize ZNP and F-ZNP using the ginger peel extract, focusing on
their safe application in antibacterial therapy and wastewater treatment.