Provided are methods of preparing, detecting, and/or assaying an analyte of interest from a sample. The methods utilize functionalized silicon membranes, such as, for example, functionalized silicon nanomembranes. Samples that can be used in the methods may be biological samples, food samples, environmental samples, industrial samples, or a combination thereof. Also provided are kits to perform methods of the present disclosure.

The present invention relates to a filter and a method of making a filter. The filter includes a porous substrate and a graphene oxide membrane and can be used to filter fluids.