A novel isoelectric focusing (IEF) platform for low‑input proteomics, using 3D‑printed immobilized pH gradient (IPG) carbon microbead arrays for first‑dimension prefractionation. NanoPak‑C‑IPG enables localized pI‑based protein focusing, high extraction efficiency, and direct hand‑off to all‑carbon NanoPak‑C RP‑HPLC, addressing key limitations of conventional IPG strips in single‑cell and low‑sample workflows.