Arsenic (As) is a metalloid that causes different kinds of diseases including cancer. The World Health Organization recommends a limit in drinking water of 10 µg As/L. In Colombia, the information about the potential risk for As contamination is still scarce, and its presence is reported mainly in Caldas, Nariño and Tolima departments. Accurate measurement of arsenic in drinking water requires expensive methods, sophisticated instrumentation and trained staff. Consequently, the biosensors design represent a great potential because they are cheap, sensitive and user-friendly systems. This work reports the development of three biosensors for arsenic detection in water using chromoproteins as the reporter system. Coding regions of the arsR regulatory gene of 15 native strains and 11 metagenomic clones resistant to arsenic from environments in Colombia were amplified and sequenced. The obtained sequences showed a close relationship with the arsR genes of Bacillius cereus ATCC 14579 (identity of 99 %, E=2e-64) and Escherichia coli ST540 (identity of 100 %, e=0.0). Three biosensors were assembled using the pUC18 cloning vector, the arsR gene of the metagenomic clone M19 and each one a chromoprotein as a reporter system (purple, pink or yellow). The biosensors BASmor and BASama showed a linear response between the intensity of colour or fluorescence (reporter protein) produced over the As(III) concentration allowing, respectively, a qualitative and quantitative assessment of the metalloid in aqueous solutions. Detection limits of 75 µg As(III)/L were obtained for the colour evaluation and 7.5 µg As(III)/L for the fluorescence response, respectively. The third biosensor BASros, under the evaluated conditions, did not show a relationship between As concentration and the colour intensity. These biosensors are emerging as an alternative to assess the presence of As in municipalities where there is no access to other technologies, allowing to detect and determine the prevalence of the metalloid in Colombia.