Degree one cohomology with twisted coefficients of the mapping class group

Let $\mathrm{\Gamma }$ be the mapping class group of an oriented surface $\mathrm{\Sigma }$ of genus g with r boundary components. We prove that the first cohomology group $H^1(\mathrm{\Gamma },O(M_{SL(2,C)}{)}^{\ast })$ is non-trivial, where the coefficient module is the dual of the space of algebraic functions on the $SL(2,C)$ moduli space over $\mathrm{\Sigma }$.