Biogenic Salvia species synthesized silver nanoparticles with catalytic, sensing, antimicrobial, and antioxidant properties

Abstract

Salvia (Lamiaceae family) is used as a brain tonic to improve cognitive function. The species including S. plebeia and S. moorcroftiana are locally used to cure hepatitis, cough, tumours, hemorrhoids, diarrhoea, common cold, flu, and asthma. To the best of authors' knowledge, no previous study has been conducted on synthesis of S. plebeia and S. moorcroftiana silver nanoparticles (SPAgNPs and SMAgNPs). The study was aimed to synthesize AgNPs from the subject species aqueous and ethanol extracts, and assess catalytic potential in degradation of standard and extracted (from yums, candies, and snacks) dyes, nitrophenols, and antibiotics. The study also aimed at AgNPs as probe in sensing metalloids and heavy metal ions including Pb²⁺, Cu²⁺, Fe³⁺, Ni²⁺, and Zn²⁺. From the results, it was found that Salvia aqueous extract afforded stable AgNPs in 1:9 and 1:15 (quantity of aqueous extract and silver nitrate solution concentration) whereas ethanol extract yielded AgNPs in 1:10 (quantity of ethanol extract and silver nitrate solution concentration) reacted in sunlight. The size of SPAgNPs and SMAgNPs determined by scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were 21.7 nm and 19.9 nm, with spherical, cylindrical, and deep hollow morphology. The synthesized AgNPs demonstrated significant potential as catalyst in dyes; Congo red (85 %), methylene blue (75 %), Rhodamine B (<50 %), nitrophenols; ortho-nitrophenol (95-98 %) and para-nitrophenol (95-98 %), dyes extracted from food samples including yums, candies, and snacks. The antibiotics (amoxicillin, doxycycline, levofloxacin) degraded up to 80 %-95 % degradation. Furthermore, the synthesized AgNPs as probe in sensing of Pb²⁺, Cu²⁺, and Fe³⁺ in Kabul river water, due to agglomeration, caused a significant decrease and bathochromic shift of SPR band (430 nm) when analyzed after 30 min. The Pb²⁺ ions was comparatively more agglomerated and chelated. Thus, the practical applicability of AgNPs in Pb²⁺ sensing was significant. Based on the results of this research study, the synthesized AgNPs could provide promising efficiency in wastewater treatment containing organic dyes, antibiotics, and heavy metals.

Keywords: Antibiotics; Heavy metals; S. moorcroftiana; S. plebeia; Silver nanoparticles; Snacks.

Graphical abstract

Fig. 1

Successive UV–Vis absorption spectra (200–800 nm) of aqueous extract mediated SPAgNPs and SMAgNPs synthesis in 1:9 under (a) heating (b) sunlight, (c) stirring, and (d) incubation.

Fig. 1

Successive UV–Vis absorption spectra (200–800 nm) of aqueous extract mediated SPAgNPs and SMAgNPs synthesis in 1:9 under (a) heating (b) sunlight, (c) stirring, and (d) incubation.

Fig. 2

Successive UV–Vis absorption spectra (200–800 nm) of aqueous extract mediated SPAgNPs and SMAgNPs synthesis in 1:15 under (a) heating (b) sunlight, (c) stirring, and (d) incubation.

Fig. 2

Successive UV–Vis absorption spectra (200–800 nm) of aqueous extract mediated SPAgNPs and SMAgNPs synthesis in 1:15 under (a) heating (b) sunlight, (c) stirring, and (d) incubation.

Fig. 3

Successive UV–Vis absorption spectra (200–800 nm) of ethanol extract mediated SPAgNPs and SMAgNPs synthesis in 1:15 under sunlight.

Fig. 4

FT-IR spectra of (a) S. plebeia and S. moorcroftiana aqueous and ethanol extracts, and (b) aqueous and ethanol extracts mediated SPAgNPs and SMAgNPs.

Fig. 5

(a) Surface morphology by SEM and (b) size by TEM techniques of the synthesized SPAgNPs and SMAgNPs.

Fig. 6

Successive UV–Vis absorption spectra of effect of pH and temperature on synthesized SPAgNPs and SMAgNPs.

Fig. 7

Successive UV–Vis absorption spectra of effect of salt on synthesized SPAgNPs and SMAgNPs.

Fig. 7

Successive UV–Vis absorption spectra of effect of salt on synthesized SPAgNPs and SMAgNPs.

Fig. 8

Successive UV–Vis absorption spectra for catalytic potential of SPAgNPs and SMAgNPs in (a) MB (b) CR, (c) MO, (d) RdB, (e) ONP, (f) PNP degradation, and (g–j) extracted dyes from yums, candies, and snacks.

Fig. 8

Successive UV–Vis absorption spectra for catalytic potential of SPAgNPs and SMAgNPs in (a) MB (b) CR, (c) MO, (d) RdB, (e) ONP, (f) PNP degradation, and (g–j) extracted dyes from yums, candies, and snacks.

Fig. 9

Successive UV–Vis absorption spectra of degradation of antibiotics; LFX, DXC, and AMX by SPAgNPs and SMAgNPs.

Fig. 10

Successive UV–Vis absorption spectra of SPAgNPs and SMAgNPs interaction with different concentrations of metal ion solutions of Pb⁺², Cu⁺², Fe³⁺, Ni⁺², and Zn⁺² at 0 and 30 min.

Fig. 10

Successive UV–Vis absorption spectra of SPAgNPs and SMAgNPs interaction with different concentrations of metal ion solutions of Pb⁺², Cu⁺², Fe³⁺, Ni⁺², and Zn⁺² at 0 and 30 min.

Fig. 11

UV–Vis absorption spectra of SPAgNPs and SMAgNPs interaction with of Pb⁺² ion solution in Kabul river water samples.