papers image were obtained using SEM (Thermo Fisher Scientific, Verios
5 UC) after platinum coating for 120 s. Additionally, energy-dispersive
spectroscopy and elemental mapping (EDS, Oxford Instruments, AztecLive,
and Ultim Max 65) were used in conjunction with SEM to determine the
major atoms (C, O, Si, and Au) and atomic percentage of Paper_AuNPs_CIN.
Moreover, ICP-OES was used to determine the wt % of Si and Au loading
(ICP-OES, Thermo Scientific, iCAP7400DUO). The surface atomic composition
was investigated using X-ray photoelectron spectroscopy (XPS) (Thermo
Scientific, NEXSA). To gain further insight into the chemical bonding
situation, the samples were analyzed using an FT-IR spectrometer equipped
with an attenuated total reflector (ATR) mode, in the range of 4000–400
cm–1 with a resolution of 4.0 and a scan rate of
32 scans. Additionally, the optical properties of the fabricated papers
were monitored between 200 and 800 nm by DRS (PerkinElmer, LAMBDA
950).