Detection method using nanoaggregate-embedded beads and system thereof

Abstract

The invention discloses a detection method using nanoaggregate-embedded beads and system thereof, which are characterized in that the nanoaggregate of Raman dye and metal nanoparticles is coated by an inorganic oxide to form a nanoaggregate-embedded bead, and which is then conjugated with a probe molecule to form a sensor bead. The Raman spectra of the product formed by binding of the sensor bead and an analyte in a sample is detected for determining whether the analyte exists in the sample. In embodiment, the pH of the solution of metal nanoparticles is controlled to keep at 10, and the concentration of the Raman dye is controlled to keep between 1×10 −6 M and 2×10 −6 M for reducing the size of the nanoaggregate.

1 . A detection method using nanoaggregate-embedded beads, comprising steps of:
 a) Adding a Raman dye into a solution of metal nanoparticles to generate nanoaggregates, and coating the nanoaggregates with an inorganic oxide to obtain nanoaggregate-embedded beads;   b) conjugating the nanoaggregate-embedded bead with a probe molecule to form a sensor bead;   c) detecting Raman spectra of the product formed by binding of the sensor bead and an analyte in a sample; and   d) determining whether the analyte exists in the sample according to the Raman spectra.   
     
     
         2 . The detection method of  claim 1 , wherein the step (a) further comprises a step of:
 (a1) change the pH of the solution of metal nanoparticles to control the size of the nanoaggregate.   
     
     
         3 . The detection method of  claim 2 , wherein the pH of the solution of metal nanoparticles is ranged from 7 to 12. 
     
     
         4 . The detection method of  claim 1 , wherein the step (a) further comprises a step of:
 (a2) controlling the concentration of the Raman dye between 0.1×10 −6 M and 5×10 −6 M.   
     
     
         5 . The detection method of  claim 1 , wherein the average size of the nanoaggregate is ranged 20 nm to 80 nm. 
     
     
         6 . The detection method of  claim 1 , wherein the inorganic oxide comprises silica or metal oxide. 
     
     
         7 . The detection method of  claim 1 , wherein the Raman dye is comprised of an organic molecule with isothiocyanate, thiol, or amine group, multiple sulfur atoms or multiple nitrogen atoms. 
     
     
         8 . The detection method of  claim 1 , wherein the metal nanoparticles comprise gold metal nanoparticle or silver metal nanoparticle. 
     
     
         9 . The detection method of  claim 1 , wherein the probe molecule comprises a chemoreceptor, an antibody, an antigen, a lectin, a hormone receptor, a nucleic acid, or a carbohydrate. 
     
     
         10 . The detection method of  claim 1 , wherein the step (a) further comprises a step of:
 adding a coating agent for performing the coating of inorganic oxide.   
     
     
         11 . The detection method of  claim 10 , wherein the coating agent comprises TEOS or TMOS. 
     
     
         12 . The detection method of  claim 1 , wherein the step (a) further comprises a step of:
 adding a coating assistant agent for assisting the coating of inorganic oxide.   
     
     
         13 . The detection method of  claim 12 , wherein the coating assistant agent comprises MPTMS. 
     
     
         14 . The detection method of  claim 10 , further comprising a step of:
 Adding an ammonia, wherein the concentration of the ammonia is controlled between 0.4 wt.-% and 1.6 wt.-%.   
     
     
         15 . The detection method of  claim 13 , wherein concentration of the MPTMS is ranged between 0.1×10 −6 M and 5×10 −6 M. 
     
     
         16 . The detection method of  claim 1 , wherein the analyte comprises an antibody, an antigen, a cytokine, a hormone, a growth factor, a neuropeptide, a hemoglobin, a plasma protein, an amino acid, a vitamin, a nucleic acid, a carbohydrate, a glycoprotein, a fatty acid, a phosphatidic acid, a sterol, an antibiotic, a cell, a toxin, a virus or a bacterium. 
     
     
         17 . A detection system using nanoaggregate-embedded beads, comprising:
 a light source capable of emitting a light to a product formed by binding of an analyte and a nanoaggregate-embedded bead conjugated with a probe molecule;   a first detection unit capable of detecting a first signal from the product; and   a second detection unit capable of detecting a second signal from the product;   wherein the simultaneous detection of multiple analytes existing in a sample or analytes bound at different locations on a surface of array biochip can be achieved by reading the first signal and the second signal.   
     
     
         18 . The detection system of  claim 17 , wherein the light source is a laser with wavelength ranged from 500 nm to 800 nm. 
     
     
         19 . The detection system of  claim 17 , wherein the first detection unit is a spectrometer. 
     
     
         20 . The detection system of  claim 19 , wherein the spectrometer is a Raman spectrometer. 
     
     
         21 . The detection system of  claim 17 , wherein the second detection unit is a photodetector. 
     
     
         22 . The detection system of  claim 17 , further comprising a filter capable of filtering the first signal. 
     
     
         23 . The detection system of  claim 22 , wherein the filter is a Raman filter. 
     
     
         24 . The detection method of  claim 17 , wherein the probe molecule comprises a chemoreceptor, an antibody, an antigen, a lectin, a hormone receptor, a nucleic acid, or a carbohydrate. 
     
     
         25 . The detection system of  claim 17 , wherein the analyte comprises an antibody, an antigen, a cytokine, a hormone, a growth factor, a neuropeptide, a hemoglobin, a plasma protein, an amino acid, a vitamin, a nucleic acid, a carbohydrate, a glycoprotein, a fatty acid, a phosphatidic acid, a sterol, an antibiotic, a cell, a toxin, a virus or a bacterium. 
     
     
         26 . The detection system of  claim 17 , wherein the first signal is a Raman signal. 
     
     
         27 . The detection system of  claim 17 , wherein the second signal is scattering light or transmission light.