Nanotechnology has explored tremendous development during the last decade because of its specific properties. Nanotechnology offers generous prospects in the improvement of agriculture, water treatment, and food industry. In this study, modern extraction techniques of agricultural and plant samples with advanced characterization methods were discussed. Additionally, various factors affecting during synthesis of NPs are also briefly described. The assessments of NPs in these samples are very complex and various techniques are to be used to get essential data. The outcomes estimated by these various techniques and methodologies are not constantly identical because of different samples different standardization methodology. A new challenge emerges when testing samples with low concentration. For this situation, expository techniques with high affectability are wanted to gauge low convergences of NPs. A perfect analytical technique should be able to detect plant-NP association, for example, structure, morphology, natural speciation, size, mass concentration, etc.
TopIntroduction
The expanding utilization of nanoparticles (NPs) on the planet has raised huge worries about their potential effects on biological systems, sanitation and human wellbeing, prompting for thorough examination regarding the association between NPs and crop plants (Chandran et al. 2006). In this manner, idea of plant-NPs interaction component is necessary for precise hazard appraisal to safe guard the adequate utilization of NPs (Handy et al. 2008). Nanotechnology has been generally applied on innovative products, biosensing techniques, optics, germicidal agents, memory chips, remote electrical devices and electrometers (Maruyama et al. 2016). Furthermore, in agrifarming perspectives, NPs are frequently consolidated to nano-figured pesticides, composts and nanosensors for plant safety (Serrano et al. 2014). Ascent of sap drives the transport of solutes across plants. Research confirms that built NPs accumulates in tissues of plant (Bandyopadhyay et al. 2013). There are different customized NPs with various morphology, properties and size. Designed NPs additionally show unique concoction and physical characteristics with various ecological practices and quality in correlation to mass partners, of 1 to 100 nm and high surface volume (Chaudhry et al. 2008; Joginder et al. 2017). Biosynthesis techniques follow conventional methods because of the accessibility of progressively natural substances and eco-accommodating methodology. The rich biodiversity and simplicity of plant elements have been profoundly investigated for the nanomaterials combination (Maruyama et al. 2016). Characterization of NPs during plant – NPs association with advanced instrumentation techniques have been developed to give important information about NPs association by the help of advanced microscopic imaging, chromatography, spectroscopy techniques etc. In this review, we portray the various synthesis techniques, approaches, factor affecting for the synthesis and modern characterization techniques for the synthesized NPs. Additionally, Green synthesis of leaf based NPs used in biomedical application and their nano-antimicrobial properties also briefly discussed.
Synthesis of NPs Different methods (biological, chemical and physical) are utilized for NPs synthesis. Physical strategies consist of including ball milling, thermal evaporation, layer by layer growth, plasma arcing, ultra thin films, spray pyrolysis, lithographic techniques, molecular beam epitasis, pulsed laser desorption, sputter deposition, and diffusion flame synthesis of NPs (Joerger et al. 2000). Likewise, the chemical chacaterisation protocol involves vapour deposition, electro deposition, sol gel method (Panigrahi et al. 2004), Langmuir Blodgett approaches, soft chemical techniques, catalytic methods, hydrolysed method (Pileni 1997), wet chemical process and co-precipitation techniques (Gan et al. 2012). Chemically, physical techniques are concentrated with high radiation stabilizing agents which are destructive to ecological and to human wellbeing. Thus, organic combination and green synthesis of NPs are easy steps towards bio reduction technique and lesser energy utilization during synthesis (Sathishkumar et al. 2009; Iravani 2011). So, adoption of bioresources like extracts of plant parts, fungi, bacteria, microalga are used for the NPs synthesis. In view of these special physiochemical interactions, nanoparticles are specifically noteworthy for various applications compound sensors, electronic parts, medicoanalytical imaging, pharmaceutics and therapeutics. For instance, metallic NPs like silver, gold, palladium and platinum are generally utilized from items going from restorative to pharmaceuticals and therapeutic. Gold NPs widely utilized in biomedical engineering (Sperling et al. 2008; Puvanakrishnan et al. 2012), chromatography sciences (Sykora et al. 2010), and pharmaceuticals (Cai et al. 2008; Bhumkar et al. 2007). Silver NPs have been found to contain antibacterial and mitigating properties that can promote quick treatment (Huang et al. 2007; Li et al. 2011). Platinum nanoparticles have been generally utilized in biomedical therapeutics being pure and alloyed with different NPs (Hrapovic et al. 2004) and NPs with palladium in catalyzed electro-chemical reactions (Gopidas et al. 2003; Mandali and Chand 2011), concoction biosensors (Coccia et al. 2012), electro-optical, and hostile to microbialmanagement (Brice-Profeta et al. 2005). Copper, iron, zinc oxide, and selenium (Pankhurst et al. 2003; Njagi et al. 2011; Lee et al. 2011; Brayner et al. 2006) have additionally been adopted in therapeutic medications and against bactericidal formulations (Prasad et al. 2012).
Figure 1. Graphical representation of (a) various methods for synthesis of NPs and (b) Bio-synthesis of NPs in plant samples.