S1 Supporting Information Redox Responsive Dipeptide Nanostructures Towards Targeted Cancer Therapy Sonika Chibh, a Avneet Kour, a Nitin Yadav, b Pankaj Kumar, a Pratik Yadav, c Virander Singh Chauhan* b , Jiban Jyoti Panda* a a. Institute of Nano Science and Technology, Phase-10, Sector 64, Mohali, Punjab, 160062, India. b. International Centre for Genetic Engineering and Biotechnology, New Delhi, India. c. Kirori Mal College, University of Delhi, New Delhi, India. *Corresponding Authors Prof. Virander Singh Chauhan (PhD, University of Delhi and Oxford University United Kingdom) International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg 110 067 New Delhi, India. Email: viranderschauhan@gmail.com Dr. Jiban Jyoti Panda (PhD, ICGEB New Delhi) Institute of Nano Science and Technology, Phase-10, Sector 64, Mohali, Punjab, 160062, India. Email: jyoti@inst.ac.in Results and Discussion: S1. Synthesis protocol for peptide: Synthesis of cysteine-phenylalanine, was carried out using solution phase peptide synthesis method. In brief, Boc-Cys(trt)-OH (5mM) was dissolved in anhydrous THF, the solution was chilled to −20 °C in an ice-salt bath and kept for stirring for 10 min. IBCF (5 mM) was then added to the solution followed by N-methyl morpholine (5 mM). After stirring for 20 min, a pre chilled solution of phenylalanine (6 mM) and sodium hydroxide (6 mM) in distilled-water was added. Reaction mixture was stirred over night at room temperature and concentrated in rota evaporator. The residual solution was acidified with chilled concentrated solution of citric acid. The resultant oil was extracted using ethyl acetate (3 × 15 mL) followed by washing with water