The Local Surface Plasmon Resonance Sensors Based On Silver Triangular Nanoplates

Noble metal nanomaterials are widely used in catalysis,sensing and other fields due to their unique physical and chemical properties.The silver triangular nanoplates?Ag TNPs?have high aspect ratio and adjustable local surface plasmon resonance?LSPR?characteristics,which attracts more and more attention in the field of LSPR sensor.Usually Ag TNPs was used as a probe to detect metal ions and biomolecules.Based on the unique properties of Ag TNPs,this paper extends the application in optical sensor.This paper mainly includes the following three parts:In the first part,we summarizes the properties and applications of noble metal nanomaterials with different morphologies and compositions,the synthesis of Ag TNPs,the application of noble metal nanomaterials in the detection of glucose and heavy metal ions,and puts forward the research ideas of this paper.In the second part,we develop the glucose sensor based on the LSPR characteristics of Ag TNPs.First,the gold nanoparticles with simulated enzyme properties were used to catalyze glucose to hydrogen peroxide.Then,the triangular silver nanoplates were etched with hydrogen peroxide,leading to the LSPR peaks of Ag TNPs blue-shifted and the color gradually changed from dark blue to light red.The maximum absorption wavelength of the Ag TNPs??35?l?is proportional to the concentration of glucose in the range of 0.5?M to 20?M,with a detection limit of 0.3?M.In addition,we also studied the effect of cysteine modification on the gold nanoparticles and improved the anti-interference ability of the detection system.In the third part,the Fe³⁺sensor based on the LSPR characteristics of Ag TNPs was investigated.Firstly,we study the mechanism of blue shift of the UV-vis absorption spectrum of Ag TNPs in citric acid-disodium hydrogen phosphate buffer solution.Secondly,it was found that iron ions could prevent the blue-shift of UV-vis absorption spectra of AgTNPs in citric acid-disodium hydrogen phosphate buffer solution?pH=7?.Finally,the LSPR changing value??35?l?of Fe³⁺preventing Ag TNPs UV-vis absorption spectrum shifting is relative to the concentration of glucose in the range of 0.5?M to 20?M,with a detection limit of 0.4?M.Based on the above phenomena and principles,we established a simple,sensitive and rapid detection method for Fe³⁺.