Patent ID: 9624532
Date: 2017-04-18
CPC Classifications: C12Q,Y02A

Claim:
1. A signal amplification sandwich structure for amplifying, detecting and/or quantifying an analyte or multiple different analytes in a fluid sample, wherein said structure consists of: (a) a first outer layer comprising a magnetic particle conjugated with a plurality of a first analyte binding material for binding the analyte; (b) an inner layer comprising said analyte; and (c) a second outer layer comprising a nonmagnetic particle conjugated with a plurality of a second analyte binding material for binding said analyte that is a matched pair with the first analyte binding material, and the nonmagnetic particle is also conjugated on its outer structure or temporarily filled in its inner structure with a plurality of an electrochemically detectable oligonucleotide tag in greater amounts than said analyte from said inner layer, wherein: (i) said electrochemically detectable oligonucleotide tags are for signal amplification, wherein the majority of nucleotides within said oligonucleotide tags are guanine, wherein said nucleotides within said oligonucleotide tags are selected from the group consisting of guanine, adenine, and thymine, and wherein the combination of said nucleotides produces a unique oligonucleotide tag that is used to amplify, detect and/or quantify said analyte or multiple different analytes; (ii) analyte amplification performance of said signal amplification sandwich structure can be tuned to meet the desired limit of detection by adjusting one or more of the following parameters: (a) the number of electrochemically detectable oligonucleotide tags per nonmagnetic particle; (b) the number of guanines per electrochemically detectable oligonucleotide tag; (c) the size of the nonmagnetic particle; and (d) the surface area of the nonmagnetic particle for conjugating electrochemically detectable oligonucleotide tags; (iii) the number of electrochemically detectable oligonucleotide tags per nonmagnetic particle ranges from 10 (iv) no optically detectable tags are used for amplification, detection or quantification.