Abstract: Described herein are nucleic acid-based electrochemical proximity assays (ECPAs) for sample quantification. The invention may also include a biosensor with a sensing mechanism that uses a pair of aptamers or antibodies that bind the target of interest. More specifically, the invention relates to an electrochemical-based read out of a sensing mechanism that uses a nucleic acid-based proximity assay in conjunction with a pair of aptamers or antibodies for sample quantification. The biosensor or a set of biosensors can be used either as a standalone measurement system for a single analyte target or as a component of a multiplexed cartridge for multiple analytes.

Abstract: Provided herein are aptamers for binding lipoproteins, systems for binding lipoproteins, and methods of detecting lipoproteins in a sample. The aptamers are useful for detecting the levels of lipoproteins in a biological sample and selectively detecting LDL particles in the presence of HDL particles. The aptamers can also be used as therapeutic agents against various diseases.