Abstract <p>This study presents an original analysis of heat and mass transfer in magnetohydrodynamic flow of a penta‑hybrid nanofluid, a configuration that uniquely combines five distinct nanoparticles with motile microorganisms a combination not previously explored in channel‑flow studies. By incorporating Joule heating, radiative heat transfer, chemical reactivity, and bioconvective effects, the work introduces a new framework for understanding complex thermal and solutal transport in multifunctional nanofluid systems. The governing equations are reduced from partial differential equations to ordinary differential equations using a similarity transformation, and solved semi-analytically with the differential transform method. The findings show that increasing the magnetic parameter raises the temperature profile while decreasing the transverse velocity, concentration, and microorganism profiles. Conversely, higher Reynolds numbers enhance concentration and microorganism profiles but lower the temperature profile. Increasing the rotational parameter and Eckert number increases temperature but decreases concentration and microorganism profiles. The thermophoresis parameter also raises the temperature but lowers concentration and microorganism profiles. The Nusselt number decreases with higher M and Ec but increases with higher R. Higher Schmidt and Brownian motion parameters increase the Sherwood number, whereas an increase in the thermophoresis parameter decreases it. Finally, increasing the Lewis number reduces microorganism density, while higher Peclet and Schmidt numbers increase microorganism density. This model has applications in particle cooling in electronic devices, microreactors, drug delivery systems, solar thermal technologies, and biomedical microfluidic platforms, with further potential for optimizing energy systems and advanced medical technologies.</p> Graphical abstract <p></p>