Liquid purification using magnetic nanoparticles

Abstract

Disclosed are magnetic nanoparticles and methods of using magnetic nanoparticles for selectively removing biologics, small molecules, analytes, ions, or other molecules of interest from liquids.

1 . A composition of matter comprising a magnetic nanoparticle having its surface functionalized by a moiety selected from moieties that are reactive to and combine with a predetermined target present in a liquid. 
     
     
         2 . The composition of  claim 1  where the magnetic nanoparticle is paramagnetic or superparamagnetic. 
     
     
         3 . The composition of  claim 1  where the magnetic nanoparticle is selected from the group consisting of magnetite, ulvospinel, hematite, ilmenite, maghemite, jacobsite, trevorite, magnesioferrite, pyrrhotite, greigite, troilite, goethite, lepidocrocite, feroxyhyte, iron, nickel, cobalt, awaruite, wairauite, a synthetic analogue such minerals and any combination thereof. 
     
     
         4 . The composition of  claim 1  where the magnetic nanoparticle is magnetite or maghemite. 
     
     
         5 . The composition of  claim 1  where the moiety is selected from the group consisting of dextran, a sugar, polyethylene glycol, hydroxyl modified polyethylene glycol, modified poly alkylene glycols, gold, azide, carboxyl groups, activated carbon, zeolites, amines, poly acrylic acid, and charged polymers. 
     
     
         6 . The composition of  claim 1  where the moiety is an amine. 
     
     
         7 . The composition of  claim 1  where the magnetic nanoparticle further comprises a second moiety selected from the group consisting of dextran, a sugar, polyethylene glycol, hydroxyl modified polyethylene glycol, modified poly alkylene glycols, polyvinyl alcohol, gold, azide, carboxyl groups, activated carbon, zeolites, amines, poly acrylic acid, charged polymers, polyether, polyalkylene glycol, crown ether, poly acrylic acid, macrocycle, and combinations thereof. 
     
     
         8 . The composition of  claim 7  where the second moiety is a hydroxyl modified polyethylene glycol. 
     
     
         9 . A process for producing a composition of matter comprising reacting a magnetic nanoparticle and a reactive amine moiety by silane conjugation reaction with a (3-aminoalkyl)-triethalkylsilane. 
     
     
         10 . A method of removing a target moiety from a liquid containing such target moieties comprising combining a quantity of magnetic nanoparticles with the liquid or the liquid with a quantity of magnetic nanoparticles,
 allowing the magnetic nanoparticles to form a complex with the target moieties, subjecting the liquid containing the nanoparticle-target complexes to a magnetic field such that the nanoparticle-target complexes segregate to a portion of the liquid, and separating the liquid into a first portion not containing the nanoparticle-target complexes and a second portion containing the nanoparticle-target complexes; wherein the nanoparticles have a diameter within the range of from 1 nm to 500 nm; and where the magnetic nanoparticles is superparamagnetic or paramagnetic.   
     
     
         11 . The method of  claim 10  where the first portion of the liquid not containing the nanoparticle complexes is recycled through the process of  claim 10  one or more times. 
     
     
         12 . The method of  claim 10  where the liquid contains water. 
     
     
         13 . The method of  claim 10  where the target moiety contains selenium or a selenium containing compound. 
     
     
         14 . The method of  claim 10  where the magnetic nanoparticles are magnetite nanoparticles synthesized with oleic acid and oleylamine and then surface functionalized with polyethylene glycol. 
     
     
         15 . The method of  claim 10  where the moiety is chloride ion. 
     
     
         16 . The method of  claim 10  where the moiety is sodium ion. 
     
     
         17 . The method of  claim 10  where the magnetic nanoparticles are functionalized before being combined with the liquid by the addition of a surfactant to their surface. 
     
     
         18 . The method of  claim 10  where the target is desorbed from the magnetic nanoparticle-target complexes by washing the magnetic nanoparticle-target complexes with basic or acidic solutions. 
     
     
         19 . The method of  claim 10  where the magnetic nanoparticles are functionalized with the group consisting of dextran, a sugar, polyethylene glycol, hydroxyl modified polyethylene glycol, modified poly alkylene glycols, polyvinyl alcohol, gold, azide, carboxyl groups, activated carbon, zeolites, amines, poly acrylic acid, charged polymers, polyether, polyalkylene glycol, crown ether, poly acrylic acid, macrocycle, and combinations thereof. 
     
     
         20 . The method of  claim 10 , further comprising desorbing the target moiety from the magnetic nanoparticle-target complexes by washing the magnetic nanoparticle-target complexes.