**3.3 Antifungal activity of AgNPs**

The antifungal properties of silver nanoparticles have been demonstrated against various fungal species [77, 78]; however, the underlying mechanism remains incompletely comprehended. The presence of silver nanoparticles has been observed to disrupt the integrity of the cellular membrane structure. The suggested mechanism for the antifungal activity of silver nanoparticles against *Candida albicans* species involves the inhibition of the budding process and damage to the membrane integrity [79]. The present investigation employed nano-Ag sepiolite fibers that contained monodispersed silver nanoparticles as the silver source to examine their antibacterial and antifungal properties. Soda with a low melting point. The incorporation of nanoparticles into lime glass powder resulted in favorable antibacterial and antifungal properties [80]. According to a study, the combination of fluconazole and silver nanoparticles exhibited the most significant inhibition against *Candida albicans*. The present investigation employed *Alternaria alternata* fungus for the purpose of extracellular biosynthesis of silver

nanoparticles [81]. The study determined that the growth of fungi was significantly reduced by the presence of silver nanoparticles at concentrations ranging from 30 to 200 mg/L [82]. Additionally, the supernatant of the GP-23 strain was utilized in the production of silver nanoparticles, which exhibited potent antifungal properties [83]. The utilization of *Trichoderma harzianum* cell filtrate was employed in the synthesis of silver nanoparticles, yielding their production in a mere 3 hours. Subsequent analysis via TEM revealed the presence of both ellipsoid and spherical nanoparticles, with a size range spanning from 19 to 63 nm and an average size of 34.77 nm [84]. According to Jalal et al.'s findings through transmission electron microscopy analysis, the application of silver nanoparticles on Candida cells led to a significant distortion of the cellular structure. Moreover, the augmentation of cell contraction was observed as a result of the interaction between nanoparticles and the fungal cell wall and membrane. The observed outcome was the disruption of the cellular membrane structure, which impeded the typical budding process as a result of compromised membrane integrity and damage [85]. In their study, Jalal et al. demonstrated the antimicrobial properties of silver nanoparticles derived from Syzygium cumini against Candida species. The authors concluded that these nanoparticles possess the ability to inhibit the proliferation, germ tube, and biofilm formation, as well as the secretion of hydrolytic enzymes by Candida species [86].

#### **3.4 Antiparasitic action of AgNPs**

The larvicidal properties of silver nanoparticles against Aedes aegypti [87] and Culex quinquefasciatus, which are dengue vectors, have been identified. A study was conducted by Allahverdiyev et al. to assess the impact of silver nanoparticles on the biological parameters of Leishmania tropica. The findings of this investigation have substantiated the antileishmanial properties of silver nanoparticles, which can be attributed to their ability to impede the proliferation activity of promastigotes. Additionally, it was observed that silver nanoparticles exhibited the ability to impede the viability of amastigotes within host cells, and this phenomenon was augmented by the existence of ultraviolet radiation [88]. The antiparasitic activity of silver and copper nanoparticles synthesized by Saad et al. was investigated. The results indicated that the viability of *Cryptosporidium parvum* oocysts was significantly reduced by silver nanoparticles. The results indicate that silver nanoparticles exhibited notable efficacy and safety in combatting parasitic infections caused by *Entamoeba histolytica* and *Cryptosporidium parvum* [89].

#### **3.5 Antifouling action of AgNPs**

Biofouling represents a significant obstacle encountered by the water industry and public health. The efficacy of silver nanoparticles derived from the *Rhizopus oryzae* fungal species has been evaluated for the remediation of water contaminated with pollutants. The utilization of *Lactobacillus fermentum* cells in the production of silver nanoparticles has been observed to effectively regulate biofilm formation. Additionally, the antifouling characteristics of these nanoparticles have been verified. In addition, silver nanoparticles have been utilized in various environmental applications, including but not limited to air, water, and surface disinfection [90]. A recent investigation has indicated that the direct application of silver nanoparticle coatings onto ecologically sound surfaces can lead to a proficient control of biofouling [91].

*Biological Agents for the Synthesis of Silver Nanoparticles and Their Applications DOI: http://dx.doi.org/10.5772/intechopen.112072*

#### **3.6 Antibiofilm activity**

In contemporary times, silver nanoparticles have emerged as a potential agent for impeding biofilm formation. However, the precise mechanism underlying the inhibitory effect of silver nanoparticles remains elusive. The classification of antibiofilm strategies was conducted by Chen et al. who identified two distinct categories: (i) interventions that specifically impede the formation of biofilms and (ii) the utilization of modified biomaterials in biomedical devices to prevent and resist biofilm formation [92]. Prior studies have corroborated novel methodologies for surface modification of biomedical apparatuses with the aim of impeding microbial attachment, adhesion, and proliferation [93]. The present investigation examined the antibiofilm efficacy of silver nanoparticles against multidrug-resistant Gram-negative bacterial isolates, and it was found that they successfully inhibited biofilm formation [94]. Martinez-Gutierrez et al. drew the conclusion that silver nanoparticles effectively hindered the formation of biofilms and exhibited bactericidal properties against established biofilms based on their research findings [95].

A study was conducted by Palanisamy et al. to investigate the impact of silver nanoparticles on biofilm formation. The study exhibited that the silver nanoparticles effectively hindered the development of biofilms in antibiotic-resistant strains [96]. A recent study was conducted to assess the interaction between silver nanoparticles and Pseudomonas putida biofilms. The study demonstrated that the utilization of silver nanoparticles effectively inhibited the formation of biofilms [97]. The antibiofilm activity of silver nanoparticles against biofilms created by Pseudomonas aeruginosa and Staphylococcus epidermidis was examined by Kalishwaralal et al. The application of silver nanoparticles on these organisms resulted in the suppression of biofilm formation [98]. Mohanty et al. conducted a study to assess the antibacterial efficacy of silver nanoparticles against a range of human pathogens.
