In this study, we report three new metal-free molecularly engineered pendant chromophore bearing polymers, coded POTZP1, POTZP2 and POTZP3. Push-pull methacrylate polymer-sensitizers consisting of phenothiazine as donor and oxindole as p-conjugating linker and tetrazole as anchoring/acceptor, were designed and synthesized for dye-sensitized solar cells (DSSCs). Optical, electrochemical and photovoltaic properties of the three polymers were systematically investigated. POTZP3-polymer incorporated di-anchoring tetrazole unit exhibited more effective inhibition of charge recombination and greater conducive to electron injection into TiO2 conduction band than the reference polymer (POTZP1) with only single anchor. Under AM 1.5 solar radiation (100 mW cm(-2)), the POTZP3-based DSSC device exhibited an attractive power conversion efficiency (PCE, eta) up to 5.91%, compared to 3.97% for the POTZP1-based device. The results indicate that the solar cell (TiO2/polymer) performance can be finely modulated through structural engineering of the polymer side-chain. (C) 2017 Elsevier Ltd. All rights reserved.