The present invention relates to sensitive, rapid and convenient assays for detection and or quantification of one or more analyte(s) in solution using multivalent proximity probes. The proximity probes each comprise several binding moieties, such as antibodies, and associated nucleic acid(s). When the binding moieties have bound to their analyte(s), the nucleic acids on opposite proximity probes interact with each other and a signal is generated based on this interaction. The multivalent proximity probes are especially valuable for highly sensitive and specific protein detection.