In this paper, the new sensors based on the C(4) or/and C(5) mono(heteroaryl) and di(heteroaryl) substituted pyrimidines are described. The effect of different substituents in pyrimidine ring on the detection limits and selectivity for prepared sensors are explained. The results of detection towards various nitro-explosives and volatile interferents at room temperature with use of the portable detector “Nitroscan” are shown.