This paper analytically investigates unsteady magnetohydrodynamic (MHD) flow of an electrically conductive hybrid nanofluid containing brass \(\left( {Cu_{3} Zn_{2} } \right)\) and cobalt (Co) nanoparticles in water ( \(H_{2} O\) ) across a moving vertical porous plate, with velocity and temperature slip boundary conditions. The mathematical model provides for the combined effects of gravity modulation, thermal radiation, and the Dufour effect. The purpose of our study is to determine the consequences of essential factors on temperature, velocity and concentration gradients. This work is important because it provides essential information on the nanofluid flow behaviour under the previously indicated influences. Understanding these interactions is critical for improving thermal-energy transport systems in a diversity of advanced thermal management, industrial and technical applications. The governing nonlinear partial differential equations are converted into dimension-free form via similarity variables and then resolved analytically using regular perturbation scheme. The analytical conclusions are confirmed using numerical simulations in MATLAB. Closed-form formulas for velocity, temperature, concentration, skin friction coefficient, and Nusselt number are obtained. The novel aspect of this work is that hybrid nanofluids with gravity modulation are important in advanced thermal and fluid flow systems because they combine hybrid nanofluids’ improved heat transfer features with gravity modulation's dynamic control capabilities. The results show that boosting gravity modulation \(\left( {\delta_{1} } \right)\) promotes temperature and velocity within the thermal boundary layer, but raising Schmidt number (Sc) reduces fluid velocity and concentration. Further, increasing radiation absorption (Ra) and thermal radiation (Rd) increases fluid’s temperature. Additionally, skin friction is improved by 9.17% when 1% addition of \(Cu_{3} Zn_{2} {\text{ and }}Co\) nanoparticles are incorporated to base fluid (water). The addition of brass and cobalt nanoparticles, which are renowned for their high thermal conductivity and magnetic responsiveness, considerably improves the heat transmission performance of the hybrid nanofluid.
