Yes, there are antibody-conjugated nanoparticles that can be used in immunohistochemistry (IHC) for diagnostic purposes. These conjugates are typically referred to as nanoparticle-based immunoassays or nanoimmunoassays.
Nanoparticle-based immunoassays involve the use of nanoparticles that are conjugated with antibodies or other targeting molecules to specifically bind to the target antigen or biomarker in the tissue sample. The nanoparticles can then be detected by a variety of methods, such as colorimetric, fluorescent, or magnetic resonance imaging (MRI) techniques.
Several companies offer commercial nanoparticle-based immunoassays for diagnostic purposes. For example, NanoString's GeoMx Digital Spatial Profiler system uses antibody-conjugated oligonucleotide-linked gold nanoparticles for high-throughput profiling of protein expression in tissue samples. Similarly, Ultivue offers a range of multiplexed IHC assays that use antibody-conjugated polymer nanoparticles for enhanced signal amplification and detection.
It is important to note that the use of nanoparticle-based immunoassays in clinical settings may require regulatory approval from the relevant authorities. Additionally, the accuracy and specificity of these assays can vary depending on the type of nanoparticle, antibody, and detection method used, and should be carefully validated before clinical use.