A sensor array comprising: a first planar substrate, the first planar substrate having a first planar surface of the first planar substrate; at least two coplanar electrodes disposed on the first planar surface of the first planar substrate; a dielectric layer, the dielectric layer having opposed first and second planar surfaces, the second surface of the dielectric layer being proximate to and coplanar with the first surface of the first planar substrate, the dielectric layer being comprised of dielectric material; a first reaction well and a second reaction well, the respective first and second reaction wells being a hole extending between the first surface of the dielectric layer and the first surface of the first planar substrate, the respective holes being positioned over a respective coplanar electrode and at least partially filled with at least one membrane chemistry, the membrane chemistry being in contact with the respective coplanar electrode; and at least one anti-diffusion region, the anti-diffusion region extending between the first surface of the dielectric layer and the first surface of the first planar substrate, the anti-diffusion region being devoid of the dielectric material, the anti-diffusion region being at least partially disposed in between the first reaction well and the second reaction well, the anti-diffusion region blocking at least one diffusion path extending between the first reaction well and the second reaction well, the at least one diffusion path being a route along which diffusible elements of the membrane chemistry of at least one of the first reaction well or the second reaction well diffuse through the respective dielectric layer. a first planar substrate, the first planar substrate having a first planar surface of the first planar substrate; at least two coplanar electrodes disposed on the first planar surface of the first planar substrate; a dielectric layer, the dielectric layer having opposed first and second planar surfaces, the second surface of the dielectric layer being proximate to and coplanar with the first surface of the first planar substrate, the dielectric layer being comprised of dielectric material; a first reaction well and a second reaction well, the respective first and second reaction wells being a hole extending between the first surface of the dielectric layer and the first surface of the first planar substrate, the respective holes being positioned over a respective coplanar electrode and at least partially filled with at least one membrane chemistry, the membrane chemistry being in contact with the respective coplanar electrode; and at least one anti-diffusion region, the anti-diffusion region extending between the first surface of the dielectric layer and the first surface of the first planar substrate, the anti-diffusion region being devoid of the dielectric material, the anti-diffusion region being at least partially disposed in between the first reaction well and the second reaction well, the anti-diffusion region blocking at least one diffusion path extending between the first reaction well and the second reaction well, the at least one diffusion path being a route along which diffusible elements of the membrane chemistry of at least one of the first reaction well or the second reaction well diffuse through the respective dielectric layer.