Graphing an nonlinear ODE

I have the following code:

%Electroporation Project

sym vars

D=5E-14; %diffusion coefficient for pore radius

kB=1.38E-23; %boltzmann constant

T=310; %temperature

F=0.70E-9; %max electric force

rh = 0.97E-9; %velocity constant

rt = 0.31E-9; %velocity constant

B=1.4E-19; %steric repulsion energy (beta)

rs = 0.51E-9; %minimum radius of hydrophilic pores (r star)

g=1.8E-11; %edge energy (gamma)

s=-1E-4; %sigmaeff

V = 0.3; %solving ODE for these values for both r1 and r2

rj=[-5:5]; %hypothetical range to determine fixed points

drdt=(D/(kB*T))*((V^2*F)*(rj+rt)./(1+rh)+4*B*(rs./rj).^4*(1/rj)-2*pi*g+2*pi*s*rj);

My issue is that I have to plot(rj,drdt), but I cannot seem to figure out how to get the matrix dimensions to agree!! Can someone please tell me where I should put the '.' so the matrix dimensions are equal.

I keep getting the following message and I have tried so many different combinations.

Error using /

Matrix dimensions must agree.

[Dinesh Yadav]

Can you show the actual equation for dr/dt ?