Abstract The intertextual-based e-book prototype helps students understand buffer solutions by connecting the three levels of chemical representation macroscopic submicroscopic and symbolic. This connection allows students to visualize chemical phenomena from simple to complex. The study aims to enhance students conceptual understanding using this e-book prototype. The research and development (R amp D) method followed five stages research and information gathering product development planning initial product development limited trials and initial product revision. This process yielded a highly validated e-book prototype that promotes innovation. The validation results showed high feasibility in substance (85.71%) instructional methods (90.90%) and language (100%). Experts deemed the e-book prototype highly effective in improving conceptual understanding through its intertextual approach. Pretest and posttest assessments of 30 students indicated improved conceptual understanding after using the e-book. Initially students demonstrated macroscopic and symbolic level abilities without associating the three levels of representation. After using the e-book they could connect these levels enhancing their understanding and conceptual understanding. The N_Gain scores for pretest and posttest assessments were 0.48 for the high category 0.45 for the medium category and 0.44 for the low category showing moderate improvement. The t-test results (Sig. (2-tailed) 0.000 lt 0.05) confirmed the effectiveness of the e-Book. Teacher and student responses averaged 90% and 85.5% respectively indicating that the intertextual-based e-book on buffer solutions is highly suitable as a self-learning resource to improve conceptual understanding. Keywords Prototype e-Book Intertextuality Concept Mastery Buffer Solution