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22 Biofunctionalized Nanomaterials for Sensing and Bioremediation of Pollutants

and organic pollutants by chemical reduction or catalysis, biofunctionalized

nanoparticles can be used in solid waste remediation, wastewater remediation,

and even in combating air pollution. As compared to the microbial degradation

process, which is relatively slower, biofunctionalized nanoparticles are used for

bioremediation, including the removal of intransigent organic compounds such

as tetrachloroethylene (TCE) and polyvinyl biphenyls (PCBs) is rapid and reliable.

Magnetite nanoparticles are widely used for bioremediation because of its ease of

preparation, economic production cost, and reusability. Magnetite nanoparticle bio-

functionalized with Rhodococcus erythyropolis LSSE8-1 and Pseudomonas delafieldii

showed enhanced bio-desulfurization activity, and these particles can be mobilized

and recovered easily using a magnet. Magnetic nanoparticles functionalized with

the IgG antibody had been demonstrated successfully for the removal of coliforms

from polluted water. In this technique, coliforms, attached nanoparticles, were

separated under a magnetic field.

There are various methods for sensing pollutants in trace amounts. However, the

majority of widely accepted conventional methods require sampling and ex situ

lab-based analysis. These methods require decent expertise and time and are some-

times not very accurate when a dynamic parameter is observed. In-field application

of sensors for sensing pollutants is of paramount importance. Biofunctionalized

nanoparticle-based sensors can overcome these problems. Novel enzyme and

antibody functionalized nanoparticles are highly specific and precise and produce

results quickly. These sensors can be used for both in situ and ex situ sensing appli-

cations. A wide variety of bioconjugated nanoparticle-based sensors are now able

to sense pollutants of distinct nature, including organic, inorganic, and microbes.

11-mercaptoundecanoic acid and chitosan-functionalized gold nanoparticles are

used for sensing heavy metals like lead, cadmium, and mercury. Gold nanoparticles,

along with IgG antibody and protein, were successfully investigated for the detection

of Staphylococcus aureus and Staphylococcus saprophyticus. Antibody-conjugated

quantum dots are used for the detection of a variety of microorganisms. Many

sensitive sensors are developed by targeting spore biomarker binding enzymes,

which can detect spore concentration in a very minute amount.

The biofunctionalized nanoparticle is a quantum leap for environmental

bioremediation technology. High efficiency and reliability make this technology

promising. However, with continuous evolution, concern like the toxicity of engi-

neered nanoparticles is continually being reduced. Recent advances in remediation

techniques now allow recovery of nanoparticle from the field of action, which

reduces any chances of toxicity. After the introduction of the “green production

of nanoparticles” by plants, the dependency of harmful chemicals and capping

agents will decrease in the future. In this chapter, we will see how biofunctional-

ized nanoparticles are helping us in the remediation of various pollution-related

challenges for a cleaner, better, and greener future.