Viral load quantification is a critical need for HIV management worldwide. However, the diagnostic technologies currently available are too limited by their size and expense to reach many remote and resource-limited populations. Toward the development of techniques which can be leveraged for point-of-care assays, we have investigated affinity capture of whole viruses using magnetic microparticles functionalized with antibodies or proteins targeting components of the HIV envelope. Results show the best performance from T-20, a small peptide employed in antiretroviral pharmacotherapy which targets an HIV envelope protein. This demonstration introduces an interesting alternative to antibodies for future affinity-capture applications in HIV diagnostics.