Graphene is a potential candidate as a counter electrode (CE) material to replace the Pt for long-term stability and low-cost fabrication of dye-sensitized solar cells (DSSC). Although the catalytic activity of graphene towards iodine-based redox mediator is not significantly high, it exhibited excellent electrocatalytic activity for cobalt-based redox mediators. However, the low adhesion capacity of graphene with FTO and low stability is the significant problems of graphene based CE for the development of long-term stable DSSCs. This research demonstrated the fabrication of highly stable with strong adhesion capacity based graphene nanoplatelets (GnP) CEs for organic DSSCs. We used conducting polymer (PEDOT:PSS) together with GnPs to improve the adhesion, stability, and catalytic activity. Different weight percent (%) of GnPs were mixed with PEDOT:PSS (PP), and subsequently dispersed by ultrasonication. The dispersed solutions were deposited on FTO by an electro spray (e-spray) method and their electro-catalytic properties were measured for Co(bpy)₃^2+/3+ redox couple (bpy=2,2′-bipyridine). The optimal PP/GnP (PPG) CE with 1wt% GnP mixed PP exhibited the profound improvement in conductivity, eletrocatalytic activity, and electrochemical stability for the Co(bpy)₃^2+/3+ redox couple compared to the Pt, GnP, and PP CEs. The charge transfer resistance (R_CT) of the optimal PPG CE at the CE/electrolyte interface was 0.07 W.cm², which is much lower than that of Pt CE (1.02 W.cm²). Moreover, the optimal PPG CEs showed better electrochemical stability under prolonged potential cycling. The DSSCs based on the Y123 sensitizer and optimal PPG CE showed a higher photovoltaic performance (J_sc, FF, and h of 13.64 mA/cm², 67.01%, and 8.33%, respectively) than those of Pt-CE (J_sc, FF, and h of 13.27 mA/cm², 65.52%, and 7.99%, respectively), GnP-CE (J_sc, FF, and h of 12.74 mA/cm², 65.69%, and 7.61%, respectively), and PP-CE (J_sc, FF, and h of 12.27 mA/cm², 60.72%, and 7.03%, respectively).