The authors describe a method for synthesis of a nanomaterial consisting of porous carbon encapsulated Mg-Al-Si alloy (denoted as Mg-Al-Si@PC) nanocluster. The nanocluster was synthesis by a solvothermal reaction, followed by high-temperature annealing. The nanoclusters were used as a novel immobilization platform for electrochemical sensing of rutin. The electrochemical behavior of rutin at a modified electrode was investigated by cyclic voltammetry and differential pulse voltammetry. The modified electrode demonstrates a high electrocatalytic activity toward rutin oxidation at a relatively low working potential (0.6 vs. Ag/AgCl). Under optimal conditions, the sensor has a linear response in the 1-10M rutin concentration range, and a 0.01M lower detection limit (at an S/N ratio of 3). It was successfully applied to the quantification of rutin in pharmaceutical tablets, and satisfactory results were obtained. Furthermore, the results correspond with those with the standard method and with the amounts indicated by the producer, respectively.