Preparation On The Scale Of Grass Carp Collagen Nano Silver And Detection Of Cr(?) Ions In Water

Nowadays,the preparation of nanoparticles by using natural biopolymers as carriers has been widely used.The molecular structure of collagen is rich of activate groups,such as hydroxyl?-OH?,carboxyl?-COOH?and amino?-NH₂?.Therefore,collagen could be used as a good carrier for synthesis of nanomataterials with uniform particle size and good dispersion.Nanomaterials are widely used in pharmaceutical,biological,environmental,food and heavy metal detection for its good quantum size and plasmon resonance effects.The nanoparticle colorimetric detection method has high sensitivity,visual detection,and it has a good application prospect in the field of heavy metal ion detection in water.The problem of chromium ion pollution has been a concern and traditional detection methods are complicated and expensive.Therefore,this paper prepares nano-silver materials using the scale of grass carp collagen?GSC-Col?as a carrier and detecting Cr?III?ion content in water rapidly.The research results are as follows:1?In this paper,silver nitrate,GSC-Col and tea polyphenol were used as silver source,dispersant,stabilizer and reducing agent,the nano-silver was synthesized by a chemical reduction method rapidly.The collagen nano-silver was characterized by UV-Vis spectrophotometer?UV-Vis?,fourier transform infrared spectroscopy?FTIR?,transmission electron microscopy?TEM?and X-ray diffraction?XRD?,showed that it has a UV absorption characteristic peak near 410 nm,and the obtained nano silver particles are spherical nano silver with an average particle diameter of 3.35 nm,4.45 nm and 7.25 nm,respectively.And it can be stored for 60 days at 4?,the phosphate buffer,low concentration sodium salt,ammonium salt and sulfate solution were relatively stable.2?The GSC-Col nano-silver can be used for the detection of heavy metals in water,the relationship between the concentration of different Cr?III?ions was determined by UV-Vis.That the two had a good linear relationship in a certain range of chromium ion concentration,the optimum detection range and linear regression equation were 0.5-10mg/L,y=0.11416x-0.03044,R²=0.994,respectively.The morphological changes of nano-silver particles before and after the addition of trivalent Cr?III?ions were characterized by TEM.It was found that non-cross-linked agglomeration reaction between nano-silver particles and Cr?III?ions was carried out,which was characterized by the size of nano-silver particles.When it becomes larger,the surface structure of collagen changes,and the color of the sol changes from yellow to brown.UV-Vis measurement showed that the UV absorption peak of nano-silver appeared red-shifted after Cr?III?addition and increased with the increase of Cr?III?concentration.The detection conditions were optimized,the nano-silver reacted with Cr?III?for 5 min at room temperature.The temperature,pH and the other metal ions have no effect on the detection.3?The GSC-Col nano-silver was used to determine the content of Cr?III?in tap water and river water by UV-Vis.The recovery rate of Cr?III?in tap water and river water were81-97.8%and 79.5-97.6%by spiked recovery test.The RSD was below 3%,indicating that the method has good accuracy.